Test Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments [[pp. 40519-40568]]

[Federal Register: July 13, 2005 (Volume 70, Number 133)]
[Rules and Regulations]
[Page 40519-40568]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13jy05-22]

[[pp. 40519-40568]]
Test Procedures for Testing Highway and Nonroad Engines and
Omnibus Technical Amendments

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The following situations illustrate examples that may require
special procedures:
(i) Your engine cannot operate on the specified duty cycle. In this
case, tell us in writing why you cannot satisfactorily test your engine
using this part's procedures and ask to use a different approach.
(ii) Your electronic control module requires specific input signals
that are not available during dynamometer testing. In this case, tell
us in writing what signals you will simulate, such as vehicle speed or
transmission signals, and explain why these signals are necessary for
representative testing.
(3) In a given model year, you may use procedures required for
later model year engines without request. If you upgrade your testing
facility in stages, you may rely on a combination of procedures for
current and later model year engines as long as you can ensure, using
good engineering judgment, that the combination you use for testing
does not affect your ability to show compliance with the applicable
emission standards.
(4) In a given model year, you may ask to use procedures allowed
for earlier model year engines. We will approve this only if you show
us that using the procedures allowed for earlier model years does not
affect your ability to show compliance with the applicable emission
standards.
(5) You may ask to use emission data collected using other
procedures, such as those of the California Air Resources Board or the
International Organization for Standardization. We will approve this
only if you show us that using these other procedures does not affect
your ability to show compliance with the applicable emission standards.
(6) During the 12 months following the effective date of any change
in the provisions of this part 1065, you may ask to use data collected
using procedures specified in the previously applicable version of this
part 1065. This paragraph (c)(6) does not restrict the use of carryover
certification data otherwise allowed by the standard-setting part.
(7) You may request to use alternate procedures that are equivalent
to allowed procedures, or more accurate or more precise than allowed
procedures. You may request to use a particular device or method for
laboratory testing even though it was originally designed for field
testing. The following provisions apply to requests for alternate
procedures:
(i) Applications. Follow the instructions in Sec. 1065.12.
(ii) Submission. Submit requests in writing to the Designated
Compliance Officer.
(iii) Notification. We may approve your request by telling you
directly, or we may issue guidance announcing our approval of a
specific alternate procedure, which would make additional requests for
approval unnecessary.
(d) If we require you to request approval to use other procedures
under paragraph (c) of this section, you may not use them until we
approve your request.

Sec. 1065.12 Approval of alternate procedures.

(a) To get approval for an alternate procedure under Sec.
1065.10(c), send the Designated Compliance Officer an initial written
request describing the alternate procedure and why you believe it is
equivalent to the specified procedure. We may approve your request
based on this information alone, or, as described in this section, we
may ask you to submit to us in writing supplemental information showing
that your alternate procedure is consistently and reliably at least as
accurate and repeatable as the specified procedure.
(b) We may make our approval under this section conditional upon
meeting other requirements or specifications. We may limit our
approval, for example, to certain time frames, specific duty cycles, or
specific emission standards. Based upon any supplemental information we
receive after our initial approval, we may amend a previously approved
alternate procedure to extend, limit, or discontinue its use. We intend
to publicly announce alternate procedures that we approve.
(c) Although we will make every effort to approve only alternate
procedures that completely meet our requirements, we may revoke our
approval of an alternate procedure if new information shows that it is
significantly not equivalent to the specified procedure.
If we do this, we will grant time to switch to testing using an
allowed procedure, considering the following factors:
(1) The cost, difficulty, and availability to switch to a procedure
that we allow.
(2) The degree to which the alternate procedure affects your
ability to show that your engines comply with all applicable emission
standards.
(3) Any relevant factors considered in our initial approval.
(d) If we do not approve your proposed alternate procedure based on
the information in your initial request, we may ask you to send the
following information to fully evaluate your request:
(1) Theoretical basis. Give a brief technical description
explaining why you believe the proposed alternate procedure should
result in emission measurements equivalent to those using the specified
procedure. You may include equations, figures, and references. You
should consider the full range of parameters that may affect
equivalence. For example, for a request to use a different
NO_X measurement procedure, you should theoretically relate
the alternate detection principle to the specified detection principle
over the expected concentration ranges for NO, NO₂, and
interference gases. For a request to use a different PM measurement
procedure, you should explain the principles by which the alternate
procedure quantifies particulate mass similarly to the specified
procedures. For any proportioning or integrating procedure, such as a
partial-flow dilution system, you should compare the alternate
procedure's theoretical response to the expected response of the
specified procedures.
(2) Technical description. Describe briefly any hardware or
software needed to perform the alternate procedure. You may include
dimensioned drawings, flowcharts, schematics, and component
specifications. Explain any necessary calculations or other data
manipulation.
(3) Procedure execution. Describe briefly how to perform the
alternate procedure and recommend a level of training an operator
should have to achieve acceptable results.
Summarize the installation, calibration, operation, and maintenance
procedures in a step-by-step format. Describe how any calibration is
performed using NIST-traceable standards or other similar standards we
approve. Calibration must be specified by using known quantities and
must not be specified as a comparison with other allowed procedures.
(4) Data-collection techniques. Compare measured emission results
using the proposed alternate procedure and the specified procedure, as
follows:
(i) Both procedures must be calibrated independently to NIST-
traceable standards or to other similar standards we approve.
(ii) Include measured emission results from all applicable duty
cycles. Measured emission results should show that the test engine
meets all applicable emission standards according to specified
procedures.
(iii) Use statistical methods to evaluate the emission
measurements,

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such as those described in paragraph (e) of this section.
(e) We may give you specific directions regarding methods for
statistical analysis, or we may approve other methods that you propose.
Absent any other directions from us, use a t-test and an F-test
calculated according to Sec. 1065.602 to evaluate whether your
proposed alternate procedure is equivalent to the specified procedure.
We recommend that you consult a statistician if you are unfamiliar with
these statistical tests. Perform the tests as follows:
(1) Repeat measurements for all applicable duty cycles at least
seven times for each procedure. You may use laboratory duty cycles to
evaluate field-testing procedures.
Be sure to include all available results to evaluate the precision
and accuracy of the proposed alternate procedure, as described in Sec.
1065.2.
(2) Demonstrate the accuracy of the proposed alternate procedure by
showing that it passes a two-sided t-test. Use an unpaired t-test,
unless you show that a paired t-test is appropriate under both of the
following provisions:
(i) For paired data, the population of the paired differences from
which you sampled paired differences must be independent. That is, the
probability of any given value of one paired difference is unchanged by
knowledge of the value of another paired difference. For example, your
paired data would violate this requirement if your series of paired
differences showed a distinct increase or decrease that was dependent
on the time at which they were sampled.
(ii) For paired data, the population of paired differences from
which you sampled the paired differences must have a normal (i.e.,
Gaussian) distribution. If the population of paired difference is not
normally distributed, consult a statistician for a more appropriate
statistical test, which may include transforming the data with a
mathematical function or using some kind of non-parametric test.
(3) Show that t is less than the critical t value,
t_crit, tabulated in Sec. 1065.602, for the following
confidence intervals:
(i) 90% for a proposed alternate procedure for laboratory testing.
(ii) 95% for a proposed alternate procedure for field testing.
(4) Demonstrate the precision of the proposed alternate procedure
by showing that it passes an F-test. Use a set of at least seven
samples from the reference procedure and a set of at least seven
samples from the alternate procedure to perform an F-test. The sets
must meet the following requirements:
(i) Within each set, the values must be independent. That is, the
probability of any given value in a set must be unchanged by knowledge
of another value in that set. For example, your data would violate this
requirement if a set showed a distinct increase or decrease that was
dependent upon the time at which they were sampled.
(ii) For each set, the population of values from which you sampled
must have a normal (i.e., Gaussian) distribution. If the population of
values is not normally distributed, consult a statistician for a more
appropriate statistical test, which may include transforming the data
with a mathematical function or using some kind of non-parametric test.
(iii) The two sets must be independent of each other. That is, the
probability of any given value in one set must be unchanged by
knowledge of another value in the other set. For example, your data
would violate this requirement if one value in a set showed a distinct
increase or decrease that was dependent upon a value in the other set.
Note that a trend of emission changes from an engine would not violate
this requirement.
(iv) If you collect paired data for the paired t-test in paragraph
(e)(2) in this section, use caution when selecting sets from paired
data for the F-test. If you do this, select sets that do not mask the
precision of the measurement procedure. We recommend selecting such
sets only from data collected using the same engine, measurement
instruments, and test cycle.
(5) Show that F is less than the critical F value,
F_crit, tabulated in Sec. 1065.602. If you have several F-
test results from several sets of data, show that the mean F-test value
is less than the mean critical F value for all the sets. Evaluate
F_crit, based on the following confidence intervals:
(i) 90% for a proposed alternate procedure for laboratory testing.
(ii) 95% for a proposed alternate procedure for field testing.

Sec. 1065.15 Overview of procedures for laboratory and field testing.

This section outlines the procedures to test engines that are
subject to emission standards.
(a) In the standard-setting part, we set brake-specific emission
standards in g/(kW[middot]hr) (or g/(hp[middot]hr)), for the following
constituents:
(1) Total oxides of nitrogen, NO_X.
(2) Hydrocarbons (HC), which may be expressed in the following
ways:
(i) Total hydrocarbons, THC.
(ii) Nonmethane hydrocarbons, NMHC, which results from subtracting
methane (CH₄) from THC.
(iii) Total hydrocarbon-equivalent, THCE, which results from
adjusting THC mathematically to be equivalent on a carbon-mass basis.
(iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from
adjusting NMHC mathematically to be equivalent on a carbon-mass basis.
(3) Particulate mass, PM.
(4) Carbon monoxide, CO.
(b) Note that some engines are not subject to standards for all the
emission constituents identified in paragraph (a) of this section.
(c) We set brake-specific emission standards over test intervals,
as follows:
(1) Engine operation. Engine operation is specified over a test
interval. A test interval is the time over which an engine's total mass
of emissions and its total work are determined. Refer to the standard-
setting part for the specific test intervals that apply to each engine.
Testing may involve measuring emissions and work during the following
types of engine operation:
(i) Laboratory testing. Under this type of testing, you determine
brake-specific emissions for duty-cycle testing by using an engine
dynamometer in a laboratory. This typically consists of one or more
test intervals, each defined by a duty cycle, which is a sequence of
speeds and torques that an engine must follow. If the standard-setting
part allows it, you may also simulate field testing by running on an
engine dynamometer in a laboratory.
(ii) Field testing. This type of testing consists of normal in-use
engine operation while an engine is installed in a vehicle. The
standard-setting part specifies how test intervals are defined for
field testing.
(2) Constituent determination. Determine the total mass of each
constituent over a test interval by selecting from the following methods:
(i) Continuous sampling. In continuous sampling, measure the
constituent's concentration continuously from raw or dilute exhaust.
Multiply this concentration by the continuous (raw or dilute) flow rate
at the emission sampling location to determine the constituent's flow
rate. Sum the constituent's flow rate continuously over the test
interval. This sum is the total mass of the emitted constituent.
(ii) Batch sampling. In batch sampling, continuously extract and
store a sample of raw or dilute exhaust for later measurement. Extract
a sample proportional to the raw or dilute exhaust flow rate. You may
extract and store a proportional sample of exhaust in an appropriate
container, such as a

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bag, and then measure HC, CO, and NO_X concentrations in the
container after the test interval. You may deposit PM from
proportionally extracted exhaust onto an appropriate substrate, such as
a filter. In this case, divide the PM by the amount of filtered exhaust
to calculate the PM concentration. Multiply batch sampled
concentrations by the total (raw or dilute) flow from which it was
extracted during the test interval. This product is the total mass of
the emitted constituent.
(iii) Combined sampling. You may use continuous and batch sampling
simultaneously during a test interval, as follows:
(A) You may use continuous sampling for some constituents and batch
sampling for others.
(B) You may use continuous and batch sampling for a single
constituent, with one being a redundant measurement. See Sec. 1065.201
for more information on redundant measurements.
(3) Work determination. Determine work over a test interval by one
of the following methods:
(i) Speed and torque. For laboratory testing, synchronously
multiply speed and brake torque to calculate instantaneous values for
engine brake power. Sum engine brake power over a test interval to
determine total work.
(ii) Fuel consumed and brake-specific fuel consumption. Directly
measure fuel consumed or calculate it with chemical balances of the
fuel, intake air, and exhaust. To calculate fuel consumed by a chemical
balance, you must also measure either intake-air flow rate or exhaust
flow rate. Divide the fuel consumed during a test interval by the
brake-specific fuel consumption to determine work over the test
interval. For laboratory testing, calculate the brake-specific fuel
consumption using fuel consumed and speed and torque over a test
interval. For field testing, refer to the standard-setting part and
Sec. 1065.915 for selecting an appropriate value for brake-specific
fuel consumption.
(d) Refer to Sec. 1065.650 for calculations to determine brake-
specific emissions.
(e) The following figure illustrates the allowed measurement
configurations described in this part 1065:

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Sec. 1065.20 Units of measure and overview of calculations.

(a) System of units. The procedures in this part generally follow
the International System of Units (SI), as detailed in NIST Special
Publication 811, 1995 Edition, ``Guide for the Use of the International
System of Units (SI),'' which we incorporate by reference in Sec.
1065.1010. This document is available on the Internet at
http://physics.nist.gov/Pubs/SP811/contents.html. Note the
following exceptions:
(1) We designate rotational frequency, f_n, of an
engine's crankshaft in revolutions per minute (rev/min), rather than
the SI unit of reciprocal seconds (1/s). This is based on the
commonplace use of rev/min in many engine dynamometer laboratories.
Also, we use the symbol f_n to identify rotational frequency
in rev/min, rather than the SI convention of using n. This avoids
confusion with our usage of the symbol n for a molar quantity.
(2) We designate brake-specific emissions in grams per kilowatt-
hour (g/(kW[middot]hr)), rather than the SI unit of grams per megajoule
(g/MJ). This is based on the fact that engines are generally subject to
emission standards expressed in g/kW[middot]hr. If we specify engine
standards in grams per horsepower[middot]hour (g/(hp[middot]hr)) in the
standard-setting part, convert units as specified in paragraph (d) of
this section.
(3) We designate temperatures in units of degrees Celsius ([deg]C)
unless a calculation requires an absolute temperature. In that case, we
designate temperatures in units of Kelvin (K). For conversion purposes
throughout this part, 0 [deg]C equals 273.15 K.
(b) Concentrations. This part does not rely on amounts expressed in
parts per million or similar units. Rather, we express such amounts in
the following SI units:
(1) For ideal gases, [mu]mol/mol, formerly ppm (volume).
(2) For all substances, [mu]m\3\/m\3\, formerly ppm (volume).
(3) For all substances, mg/kg, formerly ppm (mass).
(c) Absolute pressure. Measure absolute pressure directly or
calculate it as the sum of atmospheric pressure plus a differential
pressure that is referenced to atmospheric pressure.
(d) Units conversion. Use the following conventions to convert units:
(1) Testing. You may record values and perform calculations with
other units. For testing with equipment that involves other units, use
the conversion factors from NIST Special Publication 811, as described
in paragraph (a) of this section.
(2) Humidity. In this part, we identify humidity levels by
specifying dewpoint, which is the temperature at which pure water
begins to condense out of air. Use humidity conversions as described in
Sec. 1065.645.
(3) Emission standards. If your standard is in g/(hp[middot]hr)
units, convert kW to hp before any rounding by using the conversion
factor of 1 hp ( 550 ft[middot]lbf/s) = 0.7456999 kW. Round the final
value for comparison to the applicable standard.
(e) Rounding. Unless the standard-setting part specifies otherwise,
round only final values, not intermediate values. Round values to the
number of significant digits necessary to match the number of decimal
places of the applicable standard or specification. For information not
related to standards or specifications, use good engineering judgment
to record the appropriate number of significant digits.
(f) Interpretation of ranges. In this part, we specify ranges such
as ``±10% of maximum pressure'', ``(40 to 50) kPa'', or
``(30 ±10) kPa''. Interpret a range as a tolerance unless we
explicitly identify it as an accuracy, repeatability, linearity, or
noise specification. See Sec. 1065.1001 for the definition of Tolerance.
(g) Scaling of specifications with respect to a standard. Because
this part 1065 is applicable to a wide range of engines and emission
standards, some of the specifications in this part are scaled with
respect to an engine's emission standard or maximum power. This ensures
that the specification will be adequate to determine compliance, but
not overly burdensome by requiring unnecessarily high-precision
equipment. Many of these specifications are given with respect to a
``flow-weighted mean'' that is expected at the standard. Flow-weighted
mean is the mean of a quantity after it is weighted proportional to a
corresponding flow rate. For example, if a gas concentration is
measured continuously from the raw exhaust of an engine, its flow-
weighted mean concentration is the sum of the products of each recorded
concentration times its respective exhaust flow rate, divided by the
sum of the recorded flow rates. As another example, the bag
concentration from a CVS system is the same as the flow-weighted mean
concentration, because the CVS system itself flow-weights the bag
concentration. Refer to Sec. 1065.602 for information needed to
estimate and calculate flow-weighted means.

Sec. 1065.25 Recordkeeping.

The procedures in this part include various requirements to record
data or other information. Refer to the standard-setting part regarding
recordkeeping requirements. If the standard-setting part does not
specify recordkeeping requirements, store these records in any format
and on any media and keep them readily available for one year after you
send an associated application for certification, or one year after you
generate the data if they do not support an application for
certification. You must promptly send us organized, written records in
English if we ask for them. We may review them at any time.

Subpart B--Equipment Specifications

Sec. 1065.101 Overview.

(a) This subpart specifies equipment, other than measurement
instruments, related to emission testing. The provisions of this
subpart apply for all testing in laboratories. See subpart J of this
part to determine which of the provisions of this subpart apply for
field testing. This includes three broad categories of equipment--
dynamometers, engine fluid systems (such as fuel and intake-air
systems), and emission-sampling hardware.
(b) Other related subparts in this part identify measurement
instruments (subpart C), describe how to evaluate the performance of
these instruments (subpart D), and specify engine fluids and analytical
gases (subpart H).
(c) Subpart J of this part describes additional equipment that is
specific to field testing.
(d) Figures 1 and 2 of this section illustrate some of the possible
configurations of laboratory equipment. These figures are schematics
only; we do not require exact conformance to them. Figure 1 of this
section illustrates the equipment specified in this subpart and gives
some references to sections in this subpart. Figure 2 of this section
illustrates some of the possible configurations of a full-flow
dilution, constant-volume sampling (CVS) system. Not all possible CVS
configurations are shown.

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Sec. 1065.110 Work inputs and outputs, accessory work, and operator
demand.

(a) Work. Use good engineering judgment to simulate all engine work
inputs and outputs as they typically would operate in use. Account for
work inputs and outputs during an emission test by measuring them; or,
if they are small, you may show by engineering analysis that
disregarding them does not affect your ability to determine the net
work output by more than ±0.5% of the net reference work
output over the test interval. Use equipment to simulate the specific
types of work, as follows:
(1) Shaft work. Use an engine dynamometer that is able to meet the
cycle-validation criteria in Sec. 1065.514 over each applicable duty
cycle.
(i) You may use eddy-current and water-brake dynamometers for any
testing that does not involve engine motoring, which is identified by
negative torque commands in a reference duty cycle. See the standard
setting part for reference duty cycles that are applicable to your engine.
(ii) You may use alternating-current or direct-current motoring
dynamometers for any type of testing.
(iii) You may use one or more dynamometers.
(2) Electrical work. Use one or more of the following to simulate
electrical work:
(i) Use storage batteries or capacitors that are of the type and
capacity installed in use.
(ii) Use motors, generators, and alternators that are of the type
and capacity installed in use.
(iii) Use a resistor load bank to simulate electrical loads.
(3) Pump, compressor, and turbine work. Use pumps, compressors, and
turbines that are of the type and capacity installed in use. Use
working fluids that are of the same type and thermodynamic state as
normal in-use operation.
(b) Laboratory work inputs. You may supply any laboratory inputs of
work to the engine. For example, you may supply electrical work to the
engine to operate a fuel system, and as another example you may supply
compressor work to the engine to actuate pneumatic valves. We may ask
you to show by engineering analysis your accounting of laboratory work
inputs to meet the criterion in paragraph (a) of this section.
(c) Engine accessories. You must either install or account for the
work of engine accessories required to fuel, lubricate, or heat the
engine, circulate coolant to the engine, or to operate aftertreatment
devices. Operate the engine with these accessories installed or
accounted for during all testing operations, including mapping. If
these accessories are not powered by the engine during a test, account
for the work required to perform these functions from the total work
used in brake-specific emission calculations. For air-cooled engines
only, subtract externally powered fan work from total work. We may ask
you to show by engineering analysis your accounting of engine
accessories to meet the criterion in paragraph (a) of this section.
(d) Engine starter. You may install a production-type starter.
(e) Operator demand for shaft work. Command the operator demand and
the dynamometer(s) to follow the prescribed duty cycle with set points
for engine

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speed and torque at 5 Hz (or more frequently) for transient testing or
1 Hz (or more frequently) for steady-state testing. Use a mechanical or
electronic input to control operator demand such that the engine is
able to meet the validation criteria in Sec. 1065.514 over each
applicable duty cycle. Record feedback values for engine speed and
torque at 5 Hz or more frequently for evaluating performance relative
to the cycle validation criteria. Using good engineering judgment, you
may improve control of operator demand by altering on-engine speed and
torque controls. However, if these changes result in unrepresentative
testing, you must notify us and recommend other test procedures under
Sec. 1065.10(c)(1).

Sec. 1065.120 Fuel properties and fuel temperature and pressure.

(a) Use fuels as specified in subpart H of this part.
(b) If the engine manufacturer specifies fuel temperature and
pressure tolerances and the location where they are to be measured,
then measure the fuel temperature and pressure at the specified
location to show that you are within these tolerances throughout testing.
(c) If the engine manufacturer does not specify fuel temperature
and pressure tolerances, use good engineering judgment to set and
control fuel temperature and pressure in a way that represents typical
in-use fuel temperatures and pressures.

Sec. 1065.122 Engine cooling and lubrication.

(a) Engine cooling. Cool the engine during testing so its intake-
air, oil, coolant, block, and head temperatures are within their
expected ranges for normal operation. You may use laboratory auxiliary
coolers and fans.
(1) If you use laboratory auxiliary fans you must account for work
input to the fan(s) according to Sec. 1065.110.
(2) See Sec. 1065.125 for more information related to intake-air
cooling.
(3) See Sec. 1065.127 for more information related to exhaust gas
recirculation cooling.
(4) Measure temperatures at the manufacturer-specified locations.
If the manufacturer does not specify temperature measurement locations,
then use good engineering judgment to monitor intake-air, oil, coolant,
block, and head temperatures to ensure that they are in their expected
ranges for normal operation.
(b) Forced cooldown. You may install a forced cooldown system for
an engine and an exhaust aftertreatment device according to Sec.
1065.530(a)(1).
(c) Lubricating oil. Use lubricating oils specified in Sec.
1065.740.
(d) Coolant. For liquid-cooled engines, use coolant as specified in
Sec. 1065.745.

Sec. 1065.125 Engine intake air.

(a) Use the intake-air system installed on the engine or one that
represents a typical in-use configuration. This includes the charge-air
cooling and exhaust gas recirculation systems.
(b) Measure temperature, humidity, and atmospheric pressure near
the entrance to the engine's air filter, or at the inlet to the air
intake system for engines that have no air filter. You may use a shared
atmospheric pressure meter as long as your equipment for handling
intake air maintains ambient pressure where you test the engine within
±1 kPa of the shared atmospheric pressure. You may use a
shared humidity measurement for intake air as long as your equipment
for handling intake air maintains dewpoint where you test the engine to
within +0.5 [deg]C of the shared humidity measurement.
(c) Use an air-intake restriction that represents production
engines. Make sure the intake-air restriction is between the
manufacturer's specified maximum for a clean filter and the
manufacturer's specified maximum allowed. Measure the static
differential pressure of the restriction at the location and at the
speed and torque set points specified by the manufacturer. If the
manufacturer does not specify a location, measure this pressure
upstream any turbocharger or exhaust gas recirculation system
connection to the intake air system. If the manufacturer does not
specify speed and torque points, measure this pressure while the engine
outputs maximum power. As the manufacturer, you are liable for emission
compliance for all values up to the maximum restriction you specify for
a particular engine.
(d) This paragraph (d) includes provisions for simulating charge-
air cooling in the laboratory. This approach is described in paragraph
(d)(1) of this section. Limits on using this approach are described in
paragraphs (d)(2) and (3) of this section.
(1) Use a charge-air cooling system with a total intake-air
capacity that represents production engines' in-use installation.
Maintain coolant conditions as follows:
(i) Maintain a coolant temperature of at least 20 [deg]C at the
inlet to the charge-air cooler throughout testing.
(ii) At maximum engine power, set the coolant flow rate to achieve
an air temperature within ±5 [deg]C of the value specified
by the manufacturer at the charge-air cooler outlet. Measure the air-
outlet temperature at the location specified by the manufacturer. Use
this coolant flow rate set point throughout testing.
(2) Using a constant flow rate as described in paragraph (d)(1)(ii)
of this section may result in unrepresentative overcooling of the
intake air. If this causes any regulated emission to decrease, then you
may still use this approach, but only if the effect on emissions is
smaller than the degree to which you meet the applicable emission
standards. If the effect on emissions is larger than the degree to
which you meet the applicable emission standards, you must use a
variable flow rate that controls intake-air temperatures to be
representative of in-use operation.
(3) This approach does not apply for field testing. You may not
correct measured emission levels from field testing to account for any
differences caused by the simulated cooling in the laboratory.

Sec. 1065.127 Exhaust gas recirculation.

Use the exhaust gas recirculation (EGR) system installed with the
engine or one that represents a typical in-use configuration. This
includes any applicable EGR cooling devices.

Sec. 1065.130 Engine exhaust.

(a) General. Use the exhaust system installed with the engine or
one that represents a typical in-use configuration. This includes any
applicable aftertreatment devices.
(b) Aftertreatment configuration. If you do not use the exhaust
system installed with the engine, configure any aftertreatment devices
as follows:
(1) Position any aftertreatment device so its distance from the
nearest exhaust manifold flange or turbocharger outlet is within the
range specified by the engine manufacturer in the application for
certification. If this distance is not specified, position
aftertreatment devices to represent typical in-use vehicle configurations.
(2) You may use laboratory exhaust tubing upstream of any
aftertreatment device that is of diameter(s) typical of in-use
configurations. If you use laboratory exhaust tubing upstream of any
aftertreatment device, position each aftertreatment device according to
paragraph (b)(1) of this section.
(c) Sampling system connections. Connect an engine's exhaust system
to any raw sampling location or dilution stage, as follows:
(1) Minimize laboratory exhaust tubing lengths and use a total
length of laboratory tubing of no more than 10 m or 50 outside
diameters, whichever is greater. If laboratory exhaust tubing consists
of several different outside tubing diameters, count the number of

[[Page 40527]]

diameters of length of each individual diameter, then sum all the
diameters to determine the total length of exhaust tubing in diameters.
Use the mean outside diameter of any converging or diverging sections
of tubing. Use outside hydraulic diameters of any noncircular sections.
(2) You may install short sections of flexible laboratory exhaust
tubing at any location in the engine or laboratory exhaust systems. You
may use up to a combined total of 2 m or 10 outside diameters of
flexible exhaust tubing.
(3) Insulate any laboratory exhaust tubing downstream of the first
25 outside diameters of length.
(4) Use laboratory exhaust tubing materials that are smooth-walled,
electrically conductive, and not reactive with exhaust constituents.
Stainless steel is an acceptable material.
(5) We recommend that you use laboratory exhaust tubing that has
either a wall thickness of less than 2 mm or is air gap-insulated to
minimize temperature differences between the wall and the exhaust.
(d) In-line instruments. You may insert instruments into the
laboratory exhaust tubing, such as an in-line smoke meter. If you do
this, you may leave a length of up to 5 outside diameters of laboratory
exhaust tubing uninsulated on each side of each instrument, but you
must leave a length of no more than 25 outside diameters of laboratory
exhaust tubing uninsulated in total, including any lengths adjacent to
in-line instruments.
(e) Grounding. Electrically ground the entire exhaust system.
(f) Forced cooldown. You may install a forced cooldown system for
an exhaust aftertreatment device according to Sec. 1065.530(a)(1)(i).
(g) Exhaust restriction. Use an exhaust restriction that represents
the performance of production engines. Make sure the exhaust
restriction set point is either (80 to 100) % of the maximum exhaust
restriction specified by the manufacturer; or if the maximum is 5 kPa
or less, make sure the set point is no less than 1.0 kPa from the
maximum. For example, if the maximum back pressure is 4.5 kPa, do not
use an exhaust restriction set point that is less than 3.5 kPa. Measure
and set this pressure at the location and at the speed, torque and
aftertreatment set points specified by the manufacturer. As the
manufacturer, you are liable for emission compliance for all values up
to the maximum restriction you specify for a particular engine.
(h) Open crankcase emissions. If the standard-setting part requires
measuring open crankcase emissions, you may either measure open
crankcase emissions separately using a method that we approve in
advance, or route open crankcase emissions directly into the exhaust
system for emission measurement as follows:
(1) Use laboratory tubing materials that are smooth-walled,
electrically conductive, and not reactive with crankcase emissions.
Stainless steel is an acceptable material.
Minimize tube lengths. We also recommend using heated or thin-
walled or air gap-insulated tubing to minimize temperature differences
between the wall and the crankcase emission constituents.
(2) Minimize the number of bends in the laboratory crankcase tubing
and maximize the radius of any unavoidable bend.
(3) Use laboratory crankcase exhaust tubing that meets the engine
manufacturer's specifications for crankcase back pressure.
(4) Connect the crankcase exhaust tubing into the raw exhaust
downstream of any aftertreatment system, downstream of any installed
exhaust restriction, and sufficiently upstream of any sample probes to
ensure complete mixing with the engine's exhaust before sampling.
Extend the crankcase exhaust tube into the free stream of exhaust to
avoid boundary-layer effects and to promote mixing. You may orient the
crankcase exhaust tube's outlet in any direction relative to the raw
exhaust flow.

Sec. 1065.140 Dilution for gaseous and PM constituents.

(a) General. You may dilute exhaust with ambient air, synthetic
air, or nitrogen that is at least 15 [deg]C. Note that the composition
of the diluent affects some gaseous emission measurement instruments'
response to emissions. We recommend diluting exhaust at a location as
close as possible to the location where ambient air dilution would
occur in use.
(b) Dilution-air conditions and background concentrations. Before a
diluent is mixed with exhaust, you may precondition it by increasing or
decreasing its temperature or humidity. You may also remove
constituents to reduce their background concentrations.The following
provisions apply to removing constituents or accounting for background
concentrations:
(1) You may measure constituent concentrations in the diluent and
compensate for background effects on test results. See Sec. 1065.650
for calculations that compensate for background concentrations.
(2) Either measure these background concentrations the same way you
measure diluted exhaust constituents, or measure them in a way that
does not affect your ability to demonstrate compliance with the
applicable standards. For example, you may use the following
simplifications for background sampling:
(i) You may disregard any proportional sampling requirements.
(ii) You may use unheated gaseous sampling systems.
(iii) You may use unheated PM sampling systems only if we approve
it in advance.
(iv) You may use continuous sampling if you use batch sampling for
diluted emissions.
(v) You may use batch sampling if you use continuous sampling for
diluted emissions.
(3) For removing background PM, we recommend that you filter all
dilution air, including primary full-flow dilution air, with high-
efficiency particulate air (HEPA) filters that have an initial minimum
collection efficiency specification of 99.97% (see Sec. 1065.1001 for
procedures related to HEPA-filtration efficiencies). Ensure that HEPA
filters are installed properly so that background PM does not leak past
the HEPA filters. If you choose to correct for background PM without
using HEPA filtration, demonstrate that the background PM in the
dilution air contributes less than 50% to the net PM collected on the
sample filter.
(c) Full-flow dilution; constant-volume sampling (CVS). You may
dilute the full flow of raw exhaust in a dilution tunnel that maintains
a nominally constant volume flow rate, molar flow rate or mass flow
rate of diluted exhaust, as follows:
(1) Construction. Use a tunnel with inside surfaces of 300 series
stainless steel. Electrically ground the entire dilution tunnel. We
recommend a thin-walled and insulated dilution tunnel to minimize
temperature differences between the wall and the exhaust gases.
(2) Pressure control. Maintain static pressure at the location
where raw exhaust is introduced into the tunnel within 1.2 kPa of
atmospheric pressure. You may use a booster blower to control this
pressure. If you test an engine using more careful pressure control and
you show by engineering analysis or by test data that you require this
level of control to demonstrate compliance at the applicable standards,
we will maintain the same level of static pressure control when we test
that engine.
(3) Mixing. Introduce raw exhaust into the tunnel by directing it
downstream

[[Page 40528]]

along the centerline of the tunnel. You may introduce a fraction of
dilution air radially from the tunnel's inner surface to minimize
exhaust interaction with the tunnel walls. You may configure the system
with turbulence generators such as orifice plates or fins to achieve
good mixing. We recommend a minimum Reynolds number,
Re#, of 4000 for the diluted exhaust stream, where
Re# is based on the inside diameter of the dilution
tunnel. Re# is defined in Sec. 1065.640.
(4) Flow measurement preconditioning. You may condition the diluted
exhaust before measuring its flow rate, as long as this conditioning
takes place downstream of any sample probes, as follows:
(i) You may use flow straighteners, pulsation dampeners, or both of
these.
(ii) You may use a filter.
(iii) You may use a heat exchanger to control the temperature
upstream of any flow meter. Note paragraph (c)(6) of this section
regarding aqueous condensation.
(5) Flow measurement. Section 1065.240 describes measurement
instruments for diluted exhaust flow.
(6) Aqueous condensation. You may either prevent aqueous
condensation throughout the dilution tunnel or you may measure humidity
at the flow meter inlet. Calculations in Sec. 1065.645 and Sec.
1065.650 account for either method of addressing humidity in the
diluted exhaust. Note that preventing aqueous condensation involves
more than keeping pure water in a vapor phase (see Sec. 1065.1001).
(7) Flow compensation. Maintain nominally constant molar,
volumetric or mass flow of diluted exhaust. You may maintain nominally
constant flow by either maintaining the temperature and pressure at the
flow meter or by directly controlling the flow of diluted exhaust. You
may also directly control the flow of proportional samplers to maintain
proportional sampling. For an individual test, validate proportional
sampling as described in Sec. 1065.545.
(d) Partial-flow dilution (PFD). Except as specified in this
paragraph (d), you may dilute a partial flow of raw or previously
diluted exhaust before measuring emissions. Sec. 1065.240 describes
PFD-related flow measurement instruments. PFD may consist of constant
or varying dilution ratios as described in paragraphs (d)(2) and (3) of
this section. An example of a constant dilution ratio PFD is a
``secondary dilution PM'' measurement system. An example of a varying
dilution ratio PFD is a ``bag mini-diluter'' or BMD.
(1) Applicability. (i) You may not use PFD if the standard-setting
part prohibits it.
(ii) You may use PFD to extract a proportional raw exhaust sample
for any batch or continuous PM emission sampling over any transient
duty cycle only if we have explicitly approved it according to Sec.
1065.10 as an alternative procedure to the specified procedure for
full-flow CVS.
(iii) You may use PFD to extract a proportional raw exhaust sample
for any batch or continuous gaseous emission sampling.
(iv) You may use PFD to extract a proportional raw exhaust sample
for any batch or continuous PM emission sampling over any steady-state
duty cycle or its ramped-modal cycle (RMC) equivalent.
(v) You may use PFD to extract a proportional raw exhaust sample
for any batch or continuous field-testing.
(vi) You may use PFD to extract a proportional diluted exhaust
sample from a CVS for any batch or continuous emission sampling.
(vii) You may use PFD to extract a constant raw or diluted exhaust
sample for any continuous emission sampling.
(2) Constant dilution-ratio PFD. Do one of the following for
constant dilution-ratio PFD:
(i) Dilute an already proportional flow. For example, you may do
this as a way of performing secondary dilution from a CVS tunnel to
achieve temperature control for PM sampling.
(ii) Continuously measure constituent concentrations. For example,
you might dilute to precondition a sample of raw exhaust to control its
temperature, humidity, or constituent concentrations upstream of
continuous analyzers. In this case, you must take into account the
dilution ratio before multiplying the continuous concentration by the
sampled exhaust flow rate.
(iii) Extract a proportional sample from the constant dilution
ratio PFD system. For example, you might use a variable-flow pump to
proportionally fill a gaseous storage medium such as a bag from a PFD
system. In this case, the proportional sampling must meet the same
specifications as varying dilution ratio PFD in paragraph (d)(3) of
this section.
(3) Varying dilution-ratio PFD. All the following provisions apply
for varying dilution-ratio PFD:
(i) Use a control system with sensors and actuators that can
maintain proportional sampling over intervals as short as 200 ms (i.e.,
5 Hz control).
(ii) For control input, you may use any sensor output from one or
more measurements; for example, intake-air flow, fuel flow, exhaust
flow, engine speed, and intake manifold temperature and pressure.
(iii) Account for any emission transit time in the PFD system.
(iv) You may use preprogrammed data if they have been determined
for the specific test site, duty cycle, and test engine from which you
dilute emissions.
(v) We recommend that you run practice cycles to meet the
validation criteria in Sec. 1065.545. Note that you must validate
every emission test by meeting the validation criteria with the data
from that specific test, not from practice cycles or other tests.
(vi) You may not use a PFD system that requires preparatory tuning
or calibration with a CVS or with the emission results from a CVS.
Rather, you must be able to independently calibrate the PFD.
(e) Dilution and temperature control of PM samples. Dilute PM
samples at least once upstream of transfer lines. You may dilute PM
samples upstream of a transfer line using full-flow dilution, or
partial-flow dilution immediately downstream of a PM probe. Control
sample temperature to a (47 ±5) [deg]C tolerance, as
measured anywhere within 20 cm upstream or downstream of the PM storage
media (such as a filter). Measure this temperature with a bare-wire
junction thermocouple with wires that are (0.500 ± 0.025) mm
diameter, or with another suitable instrument that has equivalent
performance. Heat or cool the PM sample primarily by dilution.

Sec. 1065.145 Gaseous and PM probes, transfer lines, and sampling
system components.

(a) Continuous and batch sampling. Determine the total mass of each
constituent with continuous or batch sampling, as described in Sec.
1065.15(c)(2). Both types of sampling systems have probes, transfer
lines, and other sampling system components that are described in this
section.
(b) Gaseous and PM sample probes. A probe is the first fitting in a
sampling system. It protrudes into a raw or diluted exhaust stream to
extract a sample, such that its inside and outside surfaces are in
contact with the exhaust. A sample is transported out of a probe into a
transfer line, as described in paragraph (c) of this section. The
following provisions apply to probes:
(1) Probe design and construction. Use sample probes with inside
surfaces of 300 series stainless steel or, for raw exhaust sampling,
use a nonreactive material capable of withstanding raw exhaust
temperatures. Locate sample

[[Page 40529]]

probes where constituents are mixed to their mean sample concentration.
Take into account the mixing of any crankcase emissions that may be
routed into the raw exhaust. Locate each probe to minimize interference
with the flow to other probes. We recommend that all probes remain free
from influences of boundary layers, wakes, and eddies--especially near
the outlet of a raw-exhaust tailpipe where unintended dilution might
occur. Make sure that purging or back-flushing of a probe does not
influence another probe during testing. You may use a single probe to
extract a sample of more than one constituent as long as the probe
meets all the specifications for each constituent.
(2) Gaseous sample probes. Use either single-port or multi-port
probes for sampling gaseous emissions. You may orient these probes in
any direction relative to the raw or diluted exhaust flow. For some
probes, you must control sample temperatures, as follows:
(i) For probes that extract NO_X from diluted exhaust,
control the probe's wall temperature to prevent aqueous condensation.
(ii) For probes that extract hydrocarbons for NMHC or NMHCE
analysis from the diluted exhaust of compression-ignition engines, 2-
stroke spark-ignition engines, or 4-stroke spark-ignition engines below
19 kW, maintain a probe wall temperature tolerance of (191 ±
11) [deg]C.
(3) PM sample probes. Use PM probes with a single opening at the
end. Orient PM probes to face directly upstream. If you shield a PM
probe's opening with a PM pre-classifier such as a hat, you may not use
the preclassifier we specify in paragraph (d)(4)(i) of this section. We
recommend sizing the inside diameter of PM probes to approximate
isokinetic sampling at the expected mean flow rate.
(c) Transfer lines. You may use transfer lines to transport an
extracted sample from a probe to an analyzer, storage medium, or
dilution system. Minimize the length of all transfer lines by locating
analyzers, storage media, and dilution systems as close to probes as
practical. We recommend that you minimize the number of bends in
transfer lines and that you maximize the radius of any unavoidable
bend. Avoid using 90[deg]
elbows, tees, and cross-fittings in transfer
lines. Where such connections and fittings are necessary, take steps,
using good engineering judgment, to ensure that you meet the
temperature tolerances in this paragraph (c). This may involve
measuring temperature at various locations within transfer lines and
fittings. You may use a single transfer line to transport a sample of
more than one constituent, as long as the transfer line meets all the
specifications for each constituent. The following construction and
temperature tolerances apply to transfer lines:
(1) Gaseous samples. Use transfer lines with inside surfaces of 300
series stainless steel, PTFE, VitonTM, or any other material
that you demonstrate has better properties for emission sampling. For
raw exhaust sampling, use a non-reactive material capable of
withstanding raw exhaust temperatures. You may use in-line filters if
they do not react with exhaust constituents and if the filter and its
housing meet the same temperature requirements as the transfer lines,
as follows:
(i) For NO_X transfer lines upstream of either an
NO₂-to-NO converter that meets the specifications of Sec.
1065.378 or a chiller that meets the specifications of Sec. 1065.376,
maintain a sample temperature that prevents aqueous condensation.
(ii) For THC transfer lines for testing compression-ignition
engines, 2-stroke spark-ignition engines, or 4-stroke spark-ignition
engines below 19 kW, maintain a wall temperature tolerance throughout
the entire line of (191 ±11) [deg]C. If you sample from raw
exhaust, you may connect an unheated, insulated transfer line directly
to a probe. Design the length and insulation of the transfer line to
cool the highest expected raw exhaust temperature to no lower than 191
[deg]C, as measured at the transfer line's outlet.
(2) PM samples. We recommend heated transfer lines or a heated
enclosure to minimize temperature differences between transfer lines
and exhaust constituents. Use transfer lines that are inert with
respect to PM and are electrically conductive on the inside surfaces.
We recommend using PM transfer lines made of 300 series stainless
steel. Electrically ground the inside surface of PM transfer lines.
(d) Optional sample-conditioning components for gaseous sampling.
You may use the following sample-conditioning components to prepare
gaseous samples for analysis, as long you do not install or use them in
a way that adversely affects your ability to show that your engines
comply with all applicable gaseous emission standards.
(1) NO2-to-NO converter. You may use an NO₂-to-NO
converter that meets the efficiency-performance check specified in
Sec. 1065.378 at any point upstream of a NO_X analyzer,
sample bag, or other storage medium.
(2) Sample dryer. You may use either type of sample dryer described
in this paragraph (d)(2) to decrease the effects of water on gaseous
emission measurements. You may not use a chemical dryer, or used dryers
upstream of PM sample filters.
(i) Osmotic-membrane. You may use an osmotic-membrane dryer
upstream of any gaseous analyzer or storage medium, as long as it meets
the temperature specifications in paragraph (c)(1) of this section.
Because osmotic-membrane dryers may deteriorate after prolonged
exposure to certain exhaust constituents, consult with the membrane
manufacturer regarding your application before incorporating an
osmotic-membrane dryer. Monitor the dewpoint, Tdew, and absolute
pressure, ptotal, downstream of an osmotic-membrane dryer. You may use
continuously recorded values of Tdew and ptotal in the amount of water
calculations specified in Sec. 1065.645. If you do not continuously
record these values, you may use their peak values observed during a
test or their alarm setpoints as constant values in the calculations
specified in Sec. 1065.645. You may also use a nominal ptotal, which
you may estimate as the dryer's lowest absolute pressure expected
during testing.
(ii) Thermal chiller. You may use a thermal chiller upstream of
some gas analyzers and storage media. You may not use a thermal chiller
upstream of a THC measurement system for compression-ignition engines,
2-stroke spark-ignition engines, or 4-stroke spark-ignition engines
below 19 kW. If you use a thermal chiller upstream of an
NO₂-to-NO converter or in a sampling system without an
NO₂-to-NO converter, the chiller must meet the
NO₂ loss-performance check specified in Sec. 1065.376.
Monitor the dewpoint, Tdew, and absolute pressure, ptotal, downstream
of a thermal chiller. You may use continuously recorded values of Tdew
and ptotal in the emission calculations specified in Sec. 1065.650. If
you do not continuously record these values, you may use their peak
values observed during a test or their high alarm setpoints as constant
values in the amount of water calculations specified in Sec. 1065.645.
You may also use a nominal ptotal, which you may estimate as the
dryer's lowest absolute pressure expected during testing. If it is
valid to assume the degree of saturation in the thermal chiller, you
may calculate Tdew based on the known chiller efficiency and continuous
monitoring of chiller temperature, Tchiller. If you do not continuously
record values of Tchiller, you may use its peak value observed during a
test, or its alarm setpoint, as a constant value to determine a
constant amount of water according to

[[Page 40530]]

Sec. 1065.645. If it is valid to assume that Tchiller is equal to
Tdew, you may use Tchiller in lieu of Tdew according to Sec. 1065.645.
If we ask for it, you must show by engineering analysis or by data the
validity of any assumptions allowed by this paragraph (d)(2)(ii).
(3) Sample pumps. You may use sample pumps upstream of an analyzer
or storage medium for any gas. Use sample pumps with inside surfaces of
300 series stainless steel, PTFE, or any other material that you
demonstrate has better properties for emission sampling. For some
sample pumps, you must control temperatures, as follows:
(i) If you use a NO_X sample pump upstream of either an
NO₂-to-NO converter that meets Sec. 1065.378 or a chiller
that meets Sec. 1065.376, it must be heated to prevent aqueous
condensation.
(ii) For testing compression-ignition engines, 2-stroke spark-
ignition engines, or 4-stroke compression ignition engines below 19 kW,
if you use a THC sample pump upstream of a THC analyzer or storage
medium, its inner surfaces must be heated to a tolerance of (191 < plus-
minus>11) [deg]C.
(e) Optional sample-conditioning components for PM sampling. You
may use the following sample-conditioning components to prepare PM
samples for analysis, as long you do not install or use them in a way
that adversely affects your ability to show that your engines comply
with the applicable PM emission standards. You may condition PM samples
to minimize positive and negative biases to PM results, as follows:
(1) PM preclassifier. You may use a PM preclassifier to remove
large-diameter particles. The PM preclassifier may be either an
inertial impactor or a cyclonic separator. It must be constructed of
300 series stainless steel. The preclassifier must be rated to remove
at least 50% of PM at an aerodynamic diameter of 10 [mu]m and no more
than 1% of PM at an aerodynamic diameter of 1 [mu]m over the range of
flow rates for which you use it. Follow the preclassifier
manufacturer's instructions for any periodic servicing that may be
necessary to prevent a buildup of PM. Install the preclassifier in the
dilution system downstream of the last dilution stage. Configure the
preclassifier outlet with a means of bypassing any PM sample media so
the preclassifier flow may be stabilized before starting a test. Locate
PM sample media within 50 cm downstream of the preclassifier's exit.
You may not use this preclassifier if you use a PM probe that already
has a preclassifier. For example, if you use a hat-shaped preclassifier
that is located immediately upstream of the probe in such a way that it
forces the sample flow to change direction before entering the probe,
you may not use any other preclassifier in your PM sampling system.
(2) Other components. You may request to use other PM conditioning
components upstream of a PM preclassifier, such as components that
condition humidity or remove gaseous-phase hydrocarbons from the
diluted exhaust stream. You may use such components only if we approve
them under Sec. 1065.10.

Sec. 1065.150 Continuous sampling.

You may use continuous sampling techniques for measurements that
involve raw or dilute sampling. Make sure continuous sampling systems
meet the specifications in Sec. 1065.145. Make sure continuous
analyzers meet the specifications in subparts C and D of this part.

Sec. 1065.170 Batch sampling for gaseous and PM constituents.

Batch sampling involves collecting and storing emissions for later
analysis. Examples of batch sampling include collecting and storing
gaseous emissions in a bag and collecting and storing PM on a filter.
You may use batch sampling to store emissions that have been diluted at
least once in some way, such as with CVS, PFD, or BMD. You may use
batch-sampling to store undiluted emissions only if we approve it as an
alternate procedure under Sec. 1065.10.
(a) Sampling methods. For batch sampling, extract the sample at a
rate proportional to the exhaust flow. If you extract from a constant-
volume flow rate, sample at a constant-volume flow rate. If you extract
from a varying flow rate, vary the sample rate in proportion to the
varying flow rate. Validate proportional sampling after an emission
test as described in Sec. 1065.545. Use storage media that do not
change measured emission levels (either up or down). For example, do
not use sample bags for storing emissions if the bags are permeable
with respect to emissions or if they off-gas emissions. As another
example, do not use PM filters that irreversibly absorb or adsorb gases.
(b) Gaseous sample storage media. Store gas volumes in sufficiently
clean containers that minimally off-gas or allow permeation of gases.
Use good engineering judgment to determine acceptable thresholds of
storage media cleanliness and permeation. To clean a container, you may
repeatedly purge and evacuate a container and you may heat it. Use a
flexible container (such as a bag) within a temperature-controlled
environment, or use a temperature controlled rigid container that is
initially evacuated or has a volume that can be displaced, such as a
piston and cylinder arrangement. Use containers meeting the
specifications in the following table, noting that you may request to
use other container materials under Sec. 1065.10:

Table 1 of Sec. 1065.170.--Gaseous Batch Sampling Container Materials
------------------------------------------------------------------------
Engines
-----------------------------------------
Compression-ignition,
Emissions two-stroke spark All other
ignition, 4-stroke engines
spark-ignition < 19 kW
------------------------------------------------------------------------
CO, CO2, O2, CH4, C2H6, C3H8, TedlarTM,\2\ TedlarTM,\2\
NO, NO2 \1\. KynarTM,\2\ KynarTM,\2\
TeflonTM,\3\ or 300 TeflonTM,\3\ or
series stainless 300 series
steel \3\. stainless
steel\3\
THC, NMHC..................... TeflonTM \4\ or 300 TedlarTM,\2\
series stainless KynarTM,\2\
steel \4\. TeflonTM,\3\ or
300 series
stainless steel
\3\
------------------------------------------------------------------------
\1\ As long as you prevent aqueous condensation in storage container.
\2\ Up to 40 [deg]C.
\3\ Up to 202 [deg]C.
\4\ At (191 ±11) [deg]C.

(c) PM sample media. Apply the following methods for sampling
particulate emissions:
(1) If you use filter-based sampling media to extract and store PM
for measurement, your procedure must meet the following specifications:
(i) If you expect that a filter's total surface concentration of PM
will exceed

[[Page 40531]]

0.473 mm/mm\2\ for a given test interval, you may use filter media with
a minimum initial collection efficiency of 98%; otherwise you must use
a filter media with a minimum initial collection efficiency of 99.7%.
Collection efficiency must be measured as described in ASTM D 2986-95a
(incorporated by reference in Sec. 1065.1010), though you may rely on
the sample-media manufacturer's measurements reflected in their product
ratings to show that you meet applicable requirements.
(ii) The filter must be circular, with an overall diameter
of46.50± 0.6 mm and an exposed diameter of at least 38 mm.
See the cassette specifications in paragraph (c)(1)(vi) of this section.
(iii) We highly recommend that you use a pure PTFE filter material
that does not have any flow-through support bonded to the back and has
an overall thickness of 40± 20 [mu]m. An inert polymer ring
may be bonded to the periphery of the filter material for support and
for sealing between the filter cassette parts. We consider
Polymethylpentene (PMP) and PTFE inert materials for a support ring,
but other inert materials may be used. See the cassette specifications
in paragraph (c)(1)(v) of this section. We allow the use of PTFE-coated
glass fiber filter material, as long as this filter media selection
does not affect your ability to demonstrate compliance with the
applicable standards, which we base on a pure PTFE filter material.
Note that we will use pure PTFE filter material for compliance testing,
and we may require you to use pure PTFE filter material for any
compliance testing we require, such as for selective enforcement
audits.
(iv) You may request to use other filter materials or sizes under
the provisions of Sec. 1065.10.
(v) To minimize turbulent deposition and to deposit PM evenly on a
filter, use a 12.5[deg]
(from center) divergent cone angle to
transition from the transfer-line inside diameter to the exposed
diameter of the filter face. Use 300 series stainless steel for this
transition.
(vi) Maintain sample velocity at the filter face at or below 100
cm/s, where filter face velocity is the measured volumetric flow rate
of the sample at the pressure and temperature upstream of the filter
face, divided by the filter's exposed area.
(vii) Use a clean cassette designed to the specifications of Figure
1 of Sec. 1065.170 and made of any of the following materials:
Delrin\TM\, 300 series stainless steel, polycarbonate, acrylonitrile-
butadiene-styrene (ABS) resin, or conductive polypropylene. We
recommend that you keep filter cassettes clean by periodically washing
or wiping them with a compatible solvent applied using a lint-free
cloth. Depending upon your cassette material, ethanol
(C₂H₅OH) might be an acceptable solvent. Your
cleaning frequency will depend on your engine's PM and HC emissions.
(viii) If you store filters in cassettes in an automatic PM
sampler, cover or seal individual filter cassettes after sampling to
prevent communication of semi-volatile matter from one filter to another.
(2) You may use other PM sample media that we approve under Sec.
1065.10, including non-filtering techniques. For example, you might
deposit PM on an inert substrate that collects PM using electrostatic,
thermophoresis, inertia, diffusion, or some other deposition mechanism,
as approved.

BILLING CODE 6560-50-P

[[Page 40532]]
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.014
BILLING CODE 6560-50-C

Sec. 1065.190 PM-stabilization and weighing environments for
gravimetric analysis.

(a) This section describes the two environments required to
stabilize and weigh PM for gravimetric analysis: the PM stabilization
environment, where filters are stored before weighing; and the weighing
environment, where the balance is located. The two environments may
share a common space. These volumes may be one or more rooms, or they
may be much smaller, such as a glove box or an automated weighing
system consisting of one or more countertop-sized environments.
(b) We recommend that you keep both the stabilization and the
weighing environments free of ambient contaminants, such as dust,
aerosols, or semi-volatile material that could contaminate PM samples.
We recommend that these environments conform with an ``as-built'' Class
Six clean room specification according to ISO 14644-1 (incorporated by
reference in Sec. 1065.1010); however, we also recommend that you
deviate from ISO 14644-1 as necessary to minimize air motion that might
affect weighing. We recommend maximum air-supply and

[[Page 40533]]

air-return velocities of 0.05 m/s in the weighing environment.
(c) Verify the cleanliness of the PM-stabilization environment
using reference filters, as described in Sec. 1065.390(b).
(d) Maintain the following ambient conditions within the two
environments during all stabilization and weighing:
(1) Ambient temperature and tolerances. Maintain the weighing
environment at a tolerance of (22 ±1) [deg]C. If the two
environments share a common space, maintain both environments at a
tolerance of (22 ±1) [deg]C. If they are separate, maintain
the stabilization environment at a tolerance of (22 ±3)
[deg]C.
(2) Dewpoint. Maintain a dewpoint of 9.5 [deg]C in both
environments. This dewpoint will control the amount of water associated
with sulfuric acid (H₂SO₄) PM, such that 1.1368
grams of water will be associated with each gram of
H₂SO₄.
(3) Dewpoint tolerances. If the expected fraction of sulfuric acid
in PM is unknown, we recommend controlling dewpoint at within < plus-
minus>1 [deg]C tolerance. This would limit any dewpoint-related change
in PM to less than ±2%, even for PM that is 50% sulfuric
acid. If you know your expected fraction of sulfuric acid in PM, we
recommend that you select an appropriate dewpoint tolerance for showing
compliance with emission standards using the following table as a guide:

Table 1 of Sec. 1065.190.--Dewpoint Tolerance as a Function of % PM Change and % Sulfuric Acid PM
----------------------------------------------------------------------------------------------------------------
Expected sulfuric acid fraction of PM ±0.5% PM ±1.0% PM ±2.0% PM
(percent) mass change mass change mass change
----------------------------------------------------------------------------------------------------------------
5..................................... ±3.0 [deg]C. ±6.0 [deg]C. ±12 [deg]C
50.................................... ±0.30 [deg]C ±0.60 [deg]C ±1.2 [deg]C
100................................... ±0.15 [deg]C ±0.30 [deg]C ±0.60
[deg]C
----------------------------------------------------------------------------------------------------------------

(e) Verify the following ambient conditions using measurement
instruments that meet the specifications in subpart C of this part:
(1) Continuously measure dewpoint and ambient temperature. Use
these values to determine if the stabilization and weighing
environments have remained within the tolerances specified in paragraph
(d) of this section for at least the past 60 min. We recommend that you
provide an interlock that automatically prevents the balance from
reporting values if either of the environments have not been within the
applicable tolerances for the past 60 min.
(2) Continuously measure atmospheric pressure within the weighing
environment. You may use a shared atmospheric pressure meter as long as
you can show that your equipment for handling the weighing environment
air maintains ambient pressure at the balance within ±100 Pa
of the shared atmospheric pressure. Provide a means to record the most
recent atmospheric pressure when you weigh each PM sample. Use this
value to calculate the PM buoyancy correction in Sec. 1065.690.
(f) We recommend that you install a balance as follows:
(1) Install the balance on a vibration-isolation platform to
isolate it from external noise and vibration.
(2) Shield the balance from convective airflow with a static-
dissipating draft shield that is electrically grounded.
(3) Follow the balance manufacturer's specifications for all
preventive maintenance.
(4) Operate the balance manually or as part of an automated
weighing system.
(g) Minimize static electric charge in the balance environment, as
follows:
(1) Electrically ground the balance.
(2) Use 300 series stainless steel tweezers if PM samples must be
handled manually.
(3) Ground tweezers with a grounding strap, or provide a grounding
strap for the operator such that the grounding strap shares a common
ground with the balance. Make sure grounding straps have an appropriate
resistor to protect operators from accidental shock.
(4) Provide a static-electricity neutralizer that is electrically
grounded in common with the balance to remove static charge from PM
samples, as follows:
(i) You may use radioactive neutralizers such as a Polonium
(210Po) source. Replace radioactive sources at the intervals
recommended by the neutralizer manufacturer.
(ii) You may use other neutralizers, such as corona-discharge
ionizers. If you use a corona-discharge ionizer, we recommend that you
monitor it for neutral net charge according to the ionizer
manufacturer's recommendations.
(5) We recommend that you use a device to monitor the static charge
of PM sample media surfaces.
(6) We recommend that you neutralize PM sample media to within
±2.0 V of neutral.

Sec. 1065.195 PM-stabilization environment for in-situ analyzers.

(a) This section describes the environment required to determine PM
in-situ. For in-situ analyzers, such as an inertial balance, this is
the environment within a PM sampling system that surrounds the PM
sample media. This is typically a very small volume.
(b) Maintain the environment free of ambient contaminants, such as
dust, aerosols, or semi-volatile material that could contaminate PM
samples. Filter all air used for stabilization with HEPA filters.
Ensure that HEPA filters are installed properly so that background PM
does not leak past the HEPA filters.
(c) Maintain the following thermodynamic conditions within the
environment before measuring PM:
(1) Ambient temperature. Select a nominal ambient temperature,
Tamb, between (42 and 52) [deg]C. Maintain the ambient temperature
within ±1.0 [deg]C of the selected nominal value.
(2) Dewpoint. Select a dewpoint, Tdew, that corresponds to Tamb
such that Tdew = (0.95Tamb-11.40) [deg]C. The resulting dewpoint will
control the amount of water associated with sulfuric acid
(H₂SO₄) PM, such that 1.1368 grams of water will
be associated with each gram of H₂SO₄. For
example, if you select a nominal ambient temperature of 47 [deg]C, set
a dewpoint of 33.3 [deg]C.
(3) Dewpoint tolerance. If the expected fraction of sulfuric acid
in PM is unknown, we recommend controlling dewpoint within ±
1.0 [deg]C. This would limit any dewpoint-related change in PM to less
than ± 2%, even for PM that is 50% sulfuric acid. If you
know your expected fraction of sulfuric acid in PM, we recommend that
you select an appropriate dewpoint tolerance for showing compliance
with emission standards using Table 1 of Sec. 1065.190 as a guide:
(4) Absolute pressure. Maintain an absolute pressure of (80.000 to
103.325) kPa. Use good engineering judgment to

[[Page 40534]]

maintain a more stringent tolerance of absolute pressure if your PM
measurement instrument requires it.
(d) Continuously measure dewpoint, temperature, and pressure using
measurement instruments that meet the PM-stabilization environment
specifications in subpart C of this part. Use these values to determine
if the in-situ stabilization environment is within the tolerances
specified in paragraph (c) of this section. Do not use any PM
quantities that are recorded when any of these parameters exceed the
applicable tolerances.
(e) If you use an inertial PM balance, we recommend that you
install it as follows:
(1) Isolate the balance from any external noise and vibration that
is within a frequency range that could affect the balance.
(2) Follow the balance manufacturer's specifications.
(f) If static electricity affects an inertial balance, you may use
a static neutralizer, as follows:
(1) You may use a radioactive neutralizer such as a Polonium
(\210\Po) source or a Krypton (\85\Kr) source. Replace radioactive
sources at the intervals recommended by the neutralizer manufacturer.
(2) You may use other neutralizers, such as a corona-discharge
ionizer. If you use a corona-discharge ionizer, we recommend that you
monitor it for neutral net charge according to the ionizer
manufacturer's recommendations.

Subpart C--Measurement Instruments

Sec. 1065.201 Overview and general provisions.

(a) Scope. This subpart specifies measurement instruments and
associated system requirements related to emission testing in a
laboratory and in the field. This includes laboratory instruments and
portable emission measurement systems (PEMS) for measuring engine
parameters, ambient conditions, flow-related parameters, and emission
concentrations.
(b) Instrument types. You may use any of the specified instruments
as described in this subpart to perform emission tests. If you want to
use one of these instruments in a way that is not specified in this
subpart, or if you want to use a different instrument, you must first
get us to approve your alternate procedure under Sec. 1065.10. Where
we specify more than one instrument for a particular measurement, we
may identify which instrument serves as the reference for showing that
an alternative procedure is equivalent to the specified procedure.
(c) Measurement systems. Assemble a system of measurement
instruments that allows you to show that your engines comply with the
applicable emission standards, using good engineering judgment. When
selecting instruments, consider how conditions such as vibration,
temperature, pressure, humidity, viscosity, specific heat, and exhaust
composition (including trace concentrations) may affect instrument
compatibility and performance.
(d) Redundant systems. For all measurement instruments described in
this subpart, you may use data from multiple instruments to calculate
test results for a single test. If you use redundant systems, use good
engineering judgment to use multiple measured values in calculations or
to disregard individual measurements. Note that you must keep your
results from all measurements, as described in Sec. 1065.25. This
requirements applies whether or not you actually use the measurements
in your calculations.
(e) Range. You may use an instrument's response above 100% of its
operating range if this does not affect your ability to show that your
engines comply with the applicable emission standards. Note that we
require additional testing and reporting if an analyzer responds above
100% of its range. See Sec. 1065.550. Auto-ranging analyzers do not
require additional testing or reporting.
(f) Related subparts for laboratory testing. Subpart D of this part
describes how to evaluate the performance of the measurement
instruments in this subpart. In general, if an instrument is specified
in a specific section of this subpart, its calibration and
verifications are typically specified in a similarly numbered section
in subpart D of this part. For example, Sec. 1065.290 gives instrument
specifications for PM balances and Sec. 1065.390 describes the
corresponding calibrations and verifications. Note that some
instruments also have other requirements in other sections of subpart D
of this part. Subpart B of this part identifies specifications for
other types of equipment, and subpart H of this part specifies engine
fluids and analytical gases.
(g) Field testing and testing with PEMS. Subpart J of this part
describes how to use these and other measurement instruments for field
testing and other PEMS testing.

Sec. 1065.202 Data updating, recording, and control.

Your test system must be able to update data, record data and
control systems related to operator demand, the dynamometer, sampling
equipment, and measurement instruments. Use data acquisition and
control systems that can record at the specified minimum frequencies,
as follows:

Table of Sec. 1065.202.--Data Recording and Control Minimum Frequencies
----------------------------------------------------------------------------------------------------------------
Minimum command and Minimum recording
Applicable test protocol section Measured values control frequency frequency
----------------------------------------------------------------------------------------------------------------
Sec. 1065.510.................... Speed and torque during an 1 Hz.................. 1 mean value per step.
engine step-map.
Sec. 1065.510.................... Speed and torque during an 5 Hz.................. 1 Hz means.
engine sweep-map.
Sec. 1065.514, Sec. 1065.530... Transient duty cycle 5 Hz.................. 1 Hz means.
reference and feedback
speeds and torques.
Sec. 1065.514, Sec. 1065.530... Steady-state and ramped- 1 Hz.................. 1 Hz.
modal duty cycle reference
and feedback speeds and
torques.
Sec. 1065.520, Sec. 1065.530, Continuous concentrations N/A................... 1 Hz.
Sec. 1065.550. of raw or dilute analyzers.
Sec. 1065.520, Sec. 1065.530, Batch concentrations of raw N/A................... 1 mean value per test
Sec. 1065.550. or dilute analyzers. interval.
Sec. 1065.530, Sec. 1065.545... Diluted exhaust flow rate N/A................... 1 Hz.
from a CVS with a heat
exchanger upstream of the
flow measurement.
Sec. 1065.530, Sec. 1065.545... Diluted exhaust flow rate 5 Hz.................. 1 Hz means.
from a CVS without a heat
exchanger upstream of the
flow measurement.

[[Page 40535]]

Sec. 1065.530, Sec. 1065.545... Intake-air or raw-exhaust N/A................... 1 Hz means.
flow rate.
Sec. 1065.530, Sec. 1065.545... Dilution air if actively 5 Hz.................. 1 Hz means.
controlled.
Sec. 1065.530.................... Sample flow from a CVS that 1 Hz.................. 1 Hz.
has a heat exchanger.
Sec. 1065.530, Sec. 1065.545... Sample flow from a CVS does 5 Hz.................. 1 Hz mean.
not have a heat exchanger.
----------------------------------------------------------------------------------------------------------------

Sec. 1065.205 Performance specifications for measurement instruments.

Your test system as a whole must meet all the applicable
calibrations, verifications, and test-validation criteria specified in
subparts D and F of this part or subpart J of this part for using PEMS
and for performing field testing. We recommend that your instruments
meet the specifications in Table 1 of this section for all ranges you
use for testing. We also recommend that you keep any documentation you
receive from instrument manufacturers showing that your instruments
meet the specifications in Table 1 of this section.

[[Page 40536]]
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.020

Measurement of Engine Parameters and Ambient Conditions

Sec. 1065.210 Work input and output sensors.

(a) Application. Use instruments as specified in this section to
measure work inputs and outputs during engine operation. We recommend
that you use sensors, transducers, and meters that meet the
specifications in Table 1 of Sec. 1065.205. Note that your overall
systems for measuring work inputs and outputs must meet the linearity
verifications in Sec. 1065.307. We recommend that you measure work
inputs and outputs where they cross the system boundary as shown in
Figure 1 of this section. The system boundary is different for air-
cooled engines than for liquid-cooled engines. If you choose to measure
work before or after a work conversion, relative to the system
boundary, use good engineering judgment to estimate any work-conversion
losses in a way that avoids overestimation of total work. For example,
if it is impractical to instrument the shaft of an exhaust turbine
generating electrical work, you may decide to measure its converted
electrical work. In this case, divide the electrical work by an
accurate value of electrical generator efficiency ([eta]< 1), or

[[Page 40537]]

assume an efficiency of 1 ([eta]=1), which would over-estimate brake-
specific emissions. Do not underestimate the generator's efficiency
because this would result in an under-estimation of brake-specific
emissions. In all cases, ensure that you are able to accurately
demonstrate compliance with the applicable standards.

BILLING CODE 6560-50-P

[[Page 40538]]

[GRAPHIC]
[TIFF OMITTED]
TR13JY05.015
[[Page 40539]]

(b) Shaft work. Use speed and torque transducer outputs to
calculate total work according to Sec. 1065.650.
(1) Speed. Use a magnetic or optical shaft-position detector with a
resolution of at least 60 counts per revolution, in combination with a
frequency counter that rejects common-mode noise.
(2) Torque. You may use a variety of methods to determine engine
torque. As needed, and based on good engineering judgment, compensate
for torque induced by the inertia of accelerating and decelerating
components connected to the flywheel, such as the drive shaft and
dynamometer rotor. Use any of the following methods to determine engine
torque:
(i) Measure torque by mounting a strain gage or similar instrument
in-line between the engine and dynamometer.
(ii) Measure torque by mounting a strain gage or similar instrument
on a lever arm connected to the dynamometer housing.
(iii) Calculate torque from internal dynamometer signals, such as
armature current, as long as you calibrate this measurement as
described in Sec. 1065.310.
(c) Electrical work. Use a watt-hour meter output to calculate
total work according to Sec. 1065.650. Use a watt-hour meter that
outputs active power (kW). Watt-hour meters typically combine a
Wheatstone bridge voltmeter and a Hall-effect clamp-on ammeter into a
single microprocessor-based instrument that analyzes and outputs
several parameters, such as alternating or direct current voltage (V),
current (A), power factor (pf), apparent power (VA), reactive power
(VAR), and active power (W).
(d) Pump, compressor or turbine work. Use pressure transducer and
flow-meter outputs to calculate total work according to Sec. 1065.650.
For flow meters, see Sec. 1065.220 through Sec. 1065.248.

Sec. 1065.215 Pressure transducers, temperature sensors, and dewpoint
sensors.

(a) Application. Use instruments as specified in this section to
measure pressure, temperature, and dewpoint.
(b) Component requirements. We recommend that you use pressure
transducers, temperature sensors, and dewpoint sensors that meet the
specifications in Table 1 of Sec. 1065.205. Note that your overall
systems for measuring pressure, temperature, and dewpoint must meet the
calibration and verifications in Sec. 1065.315.
(c) Temperature. For PM-balance environments or other precision
temperature measurements over a narrow temperature range, we recommend
thermistors. For other applications we recommend thermocouples that are
not grounded to the thermocouple sheath. You may use other temperature
sensors, such as resistive temperature detectors (RTDs).
(d) Pressure. Pressure transducers must be located in a
temperature-controlled environment, or they must compensate for
temperature changes over their expected operating range. Transducer
materials must be compatible with the fluid being measured. For
atmospheric pressure or other precision pressure measurements, we
recommend either capacitance-type, quartz crystal, or laser-
interferometer transducers. For other applications, we recommend either
strain gage or capacitance-type pressure transducers. You may use other
pressure-measurement instruments, such as manometers, where
appropriate.
(e) Dewpoint. For PM-stabilization environments, we recommend
chilled-surface hygrometers. For other applications, we recommend thin-
film capacitance sensors. You may use other dewpoint sensors, such as a
wet-bulb/dry-bulb psychrometer, where appropriate.

Flow-Related Measurements

Sec. 1065.220 Fuel flow meter.

(a) Application. You may use fuel flow in combination with a
chemical balance of carbon (or oxygen) between the fuel, inlet air, and
raw exhaust to calculate raw exhaust flow as described in Sec.
1065.650, as follows:
(1) Use the actual value of calculated raw exhaust flow rate in the
following cases:
(i) For multiplying raw exhaust flow rate with continuously sampled
concentrations.
(ii) For multiplying total raw exhaust flow with batch-sampled
concentrations.
(2) In the following cases, you may use a fuel flow meter signal
that does not give the actual value of raw exhaust, as long as it is
linearly proportional to the exhaust molar flow rate's actual
calculated value:
(i) For feedback control of a proportional sampling system, such as
a partial-flow dilution system.
(ii) For multiplying with continuously sampled gas concentrations,
if the same signal is used in a chemical-balance calculation to
determine work from brake-specific fuel consumption and fuel consumed.
(b) Component requirements. We recommend that you use a fuel flow
meter that meets the specifications in Table 1 of Sec. 1065.205. We
recommend a fuel flow meter that measures mass directly, such as one
that relies on gravimetric or inertial measurement principles. This may
involve using a meter with one or more scales for weighing fuel or
using a Coriolis meter. Note that your overall system for measuring
fuel flow must meet the linearity verification in Sec. 1065.307 and
the calibration and verifications in Sec. 1065.320.
(c) Recirculating fuel. In any fuel-flow measurement, account for
any fuel that bypasses the engine or returns from the engine to the
fuel storage tank.
(d) Flow conditioning. For any type of fuel flow meter, condition
the flow as needed to prevent wakes, eddies, circulating flows, or flow
pulsations from affecting the accuracy or repeatability of the meter.
You may accomplish this by using a sufficient length of straight tubing
(such as a length equal to at least 10 pipe diameters) or by using
specially designed tubing bends, straightening fins, or pneumatic
pulsation dampeners to establish a steady and predictable velocity
profile upstream of the meter.

Sec. 1065.225 Intake-air flow meter.

(a) Application. You may use an intake-air flow meter in
combination with a chemical balance of carbon (or oxygen) between the
fuel, inlet air, and raw exhaust to calculate raw exhaust flow as
described in Sec. 1065.650, as follows:
(1) Use the actual value of calculated raw exhaust in the following
cases:
(i) For multiplying raw exhaust flow rate with continuously sampled
concentrations.
(ii) For multiplying total raw exhaust flow with batch-sampled
concentrations.
(2) In the following cases, you may use an intake-air flow meter
signal that does not give the actual value of raw exhaust, as long as
it is linearly proportional to the exhaust flow rate's actual
calculated value:
(i) For feedback control of a proportional sampling system, such as
a partial-flow dilution system.
(ii) For multiplying with continuously sampled gas concentrations,
if the same signal is used in a chemical-balance calculation to
determine work from brake-specific fuel consumption and fuel consumed.
(b) Component requirements. We recommend that you use an intake-air
flow meter that meets the specifications in Table 1 of Sec. 1065.205.
This may include a laminar flow element, an ultrasonic flow meter, a
subsonic venturi, a thermal-mass meter, an

[[Page 40540]]

averaging Pitot tube, or a hot-wire anemometer. Note that your overall
system for measuring intake-air flow must meet the linearity
verification in Sec. 1065.307 and the calibration in Sec. 1065.325.
(c) Flow conditioning. For any type of intake-air flow meter,
condition the flow as needed to prevent wakes, eddies, circulating
flows, or flow pulsations from affecting the accuracy or repeatability
of the meter. You may accomplish this by using a sufficient length of
straight tubing (such as a length equal to at least 10 pipe diameters)
or by using specially designed tubing bends, orifice plates or
straightening fins to establish a predictable velocity profile upstream
of the meter.

Sec. 1065.230 Raw exhaust flow meter.

(a) Application. You may use measured raw exhaust flow, as follows:
(1) Use the actual value of calculated raw exhaust in the following
cases:
(i) Multiply raw exhaust flow rate with continuously sampled
concentrations.
(ii) Multiply total raw exhaust with batch sampled concentrations.
(2) In the following cases, you may use a raw exhaust flow meter
signal that does not give the actual value of raw exhaust, as long as
it is linearly proportional to the exhaust flow rate's actual
calculated value:
(i) For feedback control of a proportional sampling system, such as
a partial-flow dilution system.
(ii) For multiplying with continuously sampled gas concentrations,
if the same signal is used in a chemical-balance calculation to
determine work from brake-specific fuel consumption and fuel consumed.
(b) Component requirements. We recommend that you use a raw-exhaust
flow meter that meets the specifications in Table 1 of Sec. 1065.205.
This may involve using an ultrasonic flow meter, a subsonic venturi, an
averaging Pitot tube, a hot-wire anemometer, or other measurement
principle. This would generally not involve a laminar flow element or a
thermal-mass meter. Note that your overall system for measuring raw
exhaust flow must meet the linearity verification in Sec. 1065.307 and
the calibration and verifications in Sec. 1065.330. Any raw-exhaust
meter must be designed to appropriately compensate for changes in the
raw exhaust's thermodynamic, fluid, and compositional states.
(c) Flow conditioning. For any type of raw exhaust flow meter,
condition the flow as needed to prevent wakes, eddies, circulating
flows, or flow pulsations from affecting the accuracy or repeatability
of the meter. You may accomplish this by using a sufficient length of
straight tubing (such as a length equal to at least 10 pipe diameters)
or by using specially designed tubing bends, orifice plates or
straightening fins to establish a predictable velocity profile upstream
of the meter.
(d) Exhaust cooling. You may cool raw exhaust upstream of a raw-
exhaust flow meter, as long as you observe all the following provisions:
(1) Do not sample PM downstream of the cooling.
(2) If cooling causes exhaust temperatures above 202 [deg]C to
decrease to below 180 [deg]C, do not sample NMHC downstream of the
cooling for compression-ignition engines, 2-stroke spark-ignition
engines, and 4-stroke spark ignition engines below 19 kW.
(3) If cooling causes aqueous condensation, do not sample
NO_X downstream of the cooling unless the cooler meets the
performance verification in Sec. 1065.376.
(4) If cooling causes aqueous condensation before the flow reaches
a flow meter, measure dewpoint, T_dew and pressure,
p_total at the flow meter inlet. Use these values in emission
calculations according to Sec. 1065.650.

Sec. 1065.240 Dilution air and diluted exhaust flow meters.

(a) Application. Use a diluted exhaust flow meter to determine
instantaneous diluted exhaust flow rates or total diluted exhaust flow
over a test interval. You may use the difference between a diluted
exhaust flow meter and a dilution air meter to calculate raw exhaust
flow rates or total raw exhaust flow over a test interval.
(b) Component requirements. We recommend that you use a diluted
exhaust flow meter that meets the specifications in Table 1 of Sec.
1065.205. Note that your overall system for measuring diluted exhaust
flow must meet the linearity verification in Sec. 1065.307 and the
calibration and verifications in Sec. 1065.340 and Sec. 1065.341. You
may use the following meters:
(1) For constant-volume sampling (CVS) of the total flow of diluted
exhaust, you may use a critical-flow venturi (CFV) or multiple
critical-flow venturis arranged in parallel, a positive-displacement
pump (PDP), a subsonic venturi (SSV), or an ultrasonic flow meter
(UFM). Combined with an upstream heat exchanger, either a CFV or a PDP
will also function as a passive flow controller in a CVS system.
However, you may also combine any flow meter with any active flow
control system to maintain proportional sampling of exhaust
constituents. You may control the total flow of diluted exhaust, or one
or more sample flows, or a combination of these flow controls to
maintain proportional sampling.
(2) For any other dilution system, you may use a laminar flow
element, an ultrasonic flow meter, a subsonic venturi, a critical-flow
venturi or multiple critical-flow venturis arranged in parallel, a
positive-displacement meter, a thermal-mass meter, an averaging Pitot
tube, or a hot-wire anemometer.
(c) Flow conditioning. For any type of diluted exhaust flow meter,
condition the flow as needed to prevent wakes, eddies, circulating
flows, or flow pulsations from affecting the accuracy or repeatability
of the meter. For some meters, you may accomplish this by using a
sufficient length of straight tubing (such as a length equal to at
least 10 pipe diameters) or by using specially designed tubing bends,
orifice plates or straightening fins to establish a predictable
velocity profile upstream of the meter.
(d) Exhaust cooling. You may cool diluted exhaust upstream of a
raw-exhaust flow meter, as long as you observe all the following
provisions:
(1) Do not sample PM downstream of the cooling.
(2) If cooling causes exhaust temperatures above 202 [deg]C to
decrease to below 180 [deg]C, do not sample NMHC downstream of the
cooling for compression-ignition engines, 2-stroke spark-ignition
engines, and 4-stroke spark ignition engines below 19 kW.
(3) If cooling causes aqueous condensation, do not sample
NO_X downstream of the cooling unless the cooler meets the
performance verification in Sec. 1065.376.
(4) If cooling causes aqueous condensation before the flow reaches
a flow meter, measure dewpoint, T_dew and pressure,
p_total at the flow meter inlet. Use these values in emission
calculations according to Sec. 1065.650.

Sec. 1065.245 Sample flow meter for batch sampling.

(a) Application. Use a sample flow meter to determine sample flow
rates or total flow sampled into a batch sampling system over a test
interval. You may use the difference between a diluted exhaust sample
flow meter and a dilution air meter to calculate raw exhaust flow rates
or total raw exhaust flow over a test interval.
(b) Component requirements. We recommend that you use a sample flow
meter that meets the specifications in

[[Page 40541]]

Table 1 of Sec. 1065.205. This may involve a laminar flow element, an
ultrasonic flow meter, a subsonic venturi, a critical-flow venturi or
multiple critical-flow venturis arranged in parallel, a positive-
displacement meter, a thermal-mass meter, an averaging Pitot tube, or a
hot-wire anemometer. Note that your overall system for measuring sample
flow must meet the linearity verification in Sec. 1065.307. For the
special case where CFVs are used for both the diluted exhaust and
sample-flow measurements and their upstream pressures and temperatures
remain similar during testing, you do not have to quantify the flow
rate of the sample-flow CFV. In this special case, the sample-flow CFV
inherently flow-weights the batch sample relative to the diluted
exhaust CFV.
(c) Flow conditioning. For any type of sample flow meter, condition
the flow as needed to prevent wakes, eddies, circulating flows, or flow
pulsations from affecting the accuracy or repeatability of the meter.
For some meters, you may accomplish this by using a sufficient length
of straight tubing (such as a length equal to at least 10 pipe
diameters) or by using specially designed tubing bends, orifice plates
or straightening fins to establish a predictable velocity profile
upstream of the meter.

Sec. 1065.248 Gas divider.

(a) Application. You may use a gas divider to blend calibration gases.
(b) Component requirements. Use a gas divider that blends gases to
the specifications of Sec. 1065.750 and to the flow-weighted
concentrations expected during testing. You may use critical-flow gas
dividers, capillary-tube gas dividers, or thermal-mass-meter gas
dividers. Note that your overall gas-divider system must meet the
linearity verification in Sec. 1065.307.

CO and CO₂ Measurements

Sec. 1065.250 Nondispersive infra-red analyzer.

(a) Application. Use a nondispersive infra-red (NDIR) analyzer to
measure CO and CO2 concentrations in raw or diluted exhaust for either
batch or continuous sampling.
(b) Component requirements. We recommend that you use an NDIR
analyzer that meets the specifications in Table 1 of Sec. 1065.205.
Note that your NDIR-based system must meet the calibration and
verifications in Sec. 1065.350 and Sec. 1065.355 and it must also
meet the linearity verification in Sec. 1065.307. You may use an NDIR
analyzer that has compensation algorithms that are functions of other
gaseous measurements and the engine's known or assumed fuel properties.
The target value for any compensation algorithm is 0.0% (that is, no
bias high and no bias low), regardless of the uncompensated signal's bias.

Hydrocarbon Measurements

Sec. 1065.260 Flame-ionization detector.

(a) Application. Use a flame-ionization detector (FID) analyzer to
measure hydrocarbon concentrations in raw or diluted exhaust for either
batch or continuous sampling. Determine hydrocarbon concentrations on a
carbon number basis of one, C₁. Determine methane and
nonmethane hydrocarbon values as described in paragraph (e) of this
section. See subpart I of this part for special provisions that apply
to measuring hydrocarbons when testing with oxygenated fuels.
(b) Component requirements. We recommend that you use a FID
analyzer that meets the specifications in Table 1 of Sec. 1065.205.
Note that your FID-based system for measuring THC, THCE, or
CH₄ must meet all of the verifications for hydrocarbon
measurement in subpart D of this part, and it must also meet the
linearity verification in Sec. 1065.307. You may use a FID that has
compensation algorithms that are functions of other gaseous
measurements and the engine's known or assumed fuel properties. The
target value for any compensation algorithm is 0.0% (that is, no bias
high and no bias low), regardless of the uncompensated signal's bias.
(c) Heated FID analyzers. For diesel-fueled engines, two-stroke
spark-ignition engines, and four-stroke spark-ignition engines below 19
kW, you must use heated FID analyzers that maintain all surfaces that
are exposed to emissions at a temperature of (191 ± 11) [deg]C.
(d) FID fuel and burner air. Use FID fuel and burner air that meet
the specifications of Sec. 1065.750. Do not allow the FID fuel and
burner air to mix before entering the FID analyzer to ensure that the
FID analyzer operates with a diffusion flame and not a premixed flame.
(e) Methane. FID analyzers measure total hydrocarbons (THC). To
determine nonmethane hydrocarbons (NMHC), quantify methane,
CH₄, either with a nonmethane cutter and a FID analyzer as
described in Sec. 1065.265, or with a gas chromatograph as described
in Sec. 1065.267. Instead of measuring methane, you may assume that 2%
of measured total hydrocarbons is methane, as described in Sec.
1065.660. For a FID analyzer used to determine NMHC, determine its
response factor to CH₄, RF_CH4, as described in
Sec. 1065.360. Note that NMHC-related calculations are described in
Sec. 1065.660.

Sec. 1065.265 Nonmethane cutter.

(a) Application. You may use a nonmethane cutter to measure
CH₄ with a FID analyzer. A nonmethane cutter oxidizes all
nonmethane hydrocarbons to CO₂ and H₂O. You may
use a nonmethane cutter for raw or diluted exhaust for batch or
continuous sampling.
(b) System performance. Determine nonmethane-cutter performance as
described in Sec. 1065.365 and use the results to calculate NMHC
emission in Sec. 1065.660.
(c) Configuration. Configure the nonmethane cutter with a bypass
line for the verification described in Sec. 1065.365.
(d) Optimization. You may optimize a nonmethane cutter to maximize
the penetration of CH₄ and the oxidation of all other
hydrocarbons. You may humidify a sample and you may dilute a sample
with purified air or oxygen (O₂) upstream of the nonmethane
cutter to optimize its performance. You must account for any sample
humidification and dilution in emission calculations.

Sec. 1065.267 Gas chromatograph.

(a) Application. You may use a gas chromatograph to measure
CH₄ concentrations of diluted exhaust for batch sampling.
While you may also use a nonmethane cutter to measure CH₄,
as described in Sec. 1065.265, use a reference procedure based on a
gas chromatograph for comparison with any proposed alternate
measurement procedure under Sec. 1065.10.
(b) Component requirements. We recommend that you use a gas
chromatograph that meets the specifications in Table 1 of Sec.
1065.205, and it must also meet the linearity verification in Sec.
1065.307.

NO_X Measurements

Sec. 1065.270 Chemiluminescent detector.

(a) Application. You may use a chemiluminescent detector (CLD) to
measure NO_X concentration in raw or diluted exhaust for
batch or continuous sampling. We generally accept a CLD for
NO_X measurement, even though it measures only NO and
NO₂, when coupled with an NO₂-to-NO converter,
since conventional engines and aftertreatment systems do not emit
significant amounts of NO_X species other than NO and
NO₂. Measure other NO_X species if required by the
standard-setting part. While you may also use other instruments to
measure NO_X, as

[[Page 40542]]

described in Sec. 1065.272, use a reference procedure based on a
chemiluminescent detector for comparison with any proposed alternate
measurement procedure under Sec. 1065.10.
(b) Component requirements. We recommend that you use a CLD that
meets the specifications in Table 1 of Sec. 1065.205. Note that your
CLD-based system must meet the quench verification in Sec. 1065.370
and it must also meet the linearity verification in Sec. 1065.307. You
may use a heated or unheated CLD, and you may use a CLD that operates
at atmospheric pressure or under a vacuum. You may use a CLD that has
compensation algorithms that are functions of other gaseous
measurements and the engine's known or assumed fuel properties. The
target value for any compensation algorithm is 0.0% (that is, no bias
high and no bias low), regardless of the uncompensated signal's bias.
(c) NO2-to-NO converter. Place upstream of the CLD an internal or
external NO₂-to-NO converter that meets the verification in
Sec. 1065.378. Configure the converter with a bypass to facilitate
this verification.
(d) Humidity effects. You must maintain all CLD temperatures to
prevent aqueous condensation. To remove humidity from a sample upstream
of a CLD, use one of the following configurations:
(1) Connect a CLD downstream of any dryer or chiller that is
downstream of an NO₂-to-NO converter that meets the
verification in Sec. 1065.378.
(2) Connect a CLD downstream of any dryer or thermal chiller that
meets the verification in Sec. 1065.376.
(e) Response time. You may use a heated CLD to improve CLD response
time.

Sec. 1065.272 Nondispersive ultraviolet analyzer.

(a) Application. You may use a nondispersive ultraviolet (NDUV)
analyzer to measure NO_X concentration in raw or diluted
exhaust for batch or continuous sampling. We generally accept an NDUV
for NO_X measurement, even though it measures only NO and
NO₂, since conventional engines and aftertreatment systems
do not emit significant amounts of other NO_X species.
Measure other NO_X species if required by the standard-
setting part.
(b) Component requirements. We recommend that you use an NDUV
analyzer that meets the specifications in Table 1 of Sec. 1065.205.
Note that your NDUV-based system must meet the verifications in Sec.
1065.372 and it must also meet the linearity verification in Sec.
1065.307. You may use a NDUV analyzer that has compensation algorithms
that are functions of other gaseous measurements and the engine's known
or assumed fuel properties. The target value for any compensation
algorithm is 0.0% (that is, no bias high and no bias low), regardless
of the uncompensated signal's bias.
(c) NO2-to-NO converter. If your NDUV analyzer measures only NO,
place upstream of the NDUV analyzer an internal or external
NO₂-to-NO converter that meets the verification in Sec.
1065.378. Configure the converter with a bypass to facilitate this
verification.
(d) Humidity effects. You must maintain NDUV temperature to prevent
aqueous condensation, unless you use one of the following
configurations:
(1) Connect an NDUV downstream of any dryer or chiller that is
downstream of an NO₂-to-NO converter that meets the
verification in Sec. 1065.378.
(2) Connect an NDUV downstream of any dryer or thermal chiller that
meets the verification in Sec. 1065.376.

O₂ Measurements

Sec. 1065.280 Paramagnetic and magnetopneumatic O₂
detection analyzers.

(a) Application. You may use a paramagnetic detection (PMD) or
magnetopneumatic detection MPD) analyzer to measure O₂
concentration in raw or diluted exhaust for batch or continuous
sampling. You may use O₂ measurements with intake air or
fuel flow measurements to calculate exhaust flow rate according to
Sec. 1065.650.
(b) Component requirements. We recommend that you use a PMD/MPD
analyzer that meets the specifications in Table 1 of Sec. 1065.205.
Note that it must meet the linearity verification in Sec. 1065.307.
You may use a PMD/MPD that has compensation algorithms that are
functions of other gaseous measurements and the engine's known or
assumed fuel properties. The target value for any compensation
algorithm is 0.0% (that is, no bias high and no bias low), regardless
of the uncompensated signal's bias.

Air-to-Fuel Ratio Measurements

Sec. 1065.284 Zirconia (ZrO₂) analyzer.

(a) Application. You may use a zirconia (ZrO₂) analyzer
to measure air-to-fuel ratio in raw exhaust for continuous sampling.
You may use O₂ measurements with intake air or fuel flow
measurements to calculate exhaust flow rate according to Sec.
1065.650.
(b) Component requirements. We recommend that you use a
ZrO₂ analyzer that meets the specifications in Table 1 of
Sec. 1065.205. Note that your ZrO₂-based system must meet
the linearity verification in Sec. 1065.307. You may use a Zirconia
analyzer that has compensation algorithms that are functions of other
gaseous measurements and the engine's known or assumed fuel properties.
The target value for any compensation algorithm is 0.0% (that is, no
bias high and no bias low), regardless of the uncompensated signal's bias.

PM Measurements

Sec. 1065.290 PM gravimetric balance.

(a) Application. Use a balance to weigh net PM on a sample medium
for laboratory testing.
(b) Component requirements. We recommend that you use a balance
that meets the specifications in Table 1 of Sec. 1065.205. Note that
your balance-based system must meet the linearity verification in Sec.
1065.307. If the balance uses internal calibration weights for routine
spanning and linearity verifications, the calibration weights must meet
the specifications in Sec. 1065.790. While you may also use an
inertial balance to measure PM, as described in Sec. 1065.295, use a
reference procedure based on a gravimetric balance for comparison with
any proposed alternate measurement procedure under Sec. 1065.10.
(c) Pan design. We recommend that you use a balance pan designed to
minimize corner loading of the balance, as follows:
(1) Use a pan that centers the PM sample on the weighing pan. For
example, use a pan in the shape of a cross that has upswept tips that
center the PM sample media on the pan.
(2) Use a pan that positions the PM sample as low as possible.
(d) Balance configuration. Configure the balance for optimum
settling time and stability at your location.

Sec. 1065.295 PM inertial balance for field-testing analysis.

(a) Application. You may use an inertial balance to quantify net PM
on a sample medium for field testing.
(b) Component requirements. We recommend that you use a balance
that meets the specifications in Table 1 of Sec. 1065.205. Note that
your balance-based system must meet the linearity verification in Sec.
1065.307. If the balance uses an internal calibration process for
routine spanning and linearity verifications, the process must be NIST-
traceable. You may use an inertial PM balance that has compensation
algorithms that are functions of other gaseous measurements and the
engine's known or assumed fuel properties. The target value for any
compensation algorithm is 0.0% (that is, no bias high

[[Page 40543]]

and no bias low), regardless of the uncompensated signal's bias.

Subpart D--Calibrations and Verifications

Sec. 1065.301 Overview and general provisions.

(a) This subpart describes required and recommended calibrations
and verifications of measurement systems. See subpart C of this part
for specifications that apply to individual instruments.
(b) You must generally use complete measurement systems when
performing calibrations or verifications in this subpart. For example,
this would generally involve evaluating instruments based on values
recorded with the complete system you use for recording test data,
including analog-to-digital converters. For some calibrations and
verifications, we may specify that you disconnect part of the
measurement system to introduce a simulated signal.
(c) If we do not specify a calibration or verification for a
portion of a measurement system, calibrate that portion of your system
and verify its performance at a frequency consistent with any
recommendations from the measurement-system manufacturer, consistent
with good engineering judgment.
(d) Use NIST-traceable standards to the tolerances we specify for
calibrations and verifications. Where we specify the need to use NIST-
traceable standards, you may alternatively ask for our approval to use
international standards that are not NIST-traceable.

Sec. 1065.303 Summary of required calibration and verifications.

The following table summarizes the required and recommended
calibrations and verifications described in this subpart and indicates
when these have to be performed:

Table 1 of Sec. 1065.303.--Summary of Required Calibration and
Verifications
------------------------------------------------------------------------
Type of calibration or
verification Minimum frequency a
------------------------------------------------------------------------
Sec. 1065.305: accuracy, Accuracy: Not required, but recommended
repeatability and noise. for initial installation.
Repeatability: Not required, but
recommended for initial installation.
Noise: Not required, but recommended for
initial installation.
Sec. 1065.307: linearity... Speed: Upon initial installation, within
370 days before testing and after major
maintenance.
Torque: Upon initial installation, within
370 days before testing and after major
maintenance.
Electrical power: Upon initial
installation, within 370 days before
testing and after major maintenance.
Clean gas and diluted exhaust flows: Upon
initial installation, within 370 days
before testing and after major
maintenance, unless flow is verified by
propane check or by carbon or oxygen
balance.
Raw exhaust flow: Upon initial
installation, within 185 days before
testing and after major maintenance,
unless flow is verified by propane check
or by carbon or oxygen balance.
Gas analyzers: Upon initial installation,
within 35 days before testing and after
major maintenance.
PM balance: Upon initial installation,
within 370 days before testing and after
major maintenance.
Stand-alone pressure and temperature:
Upon initial installation, within 370
days before testing and after major
maintenance.
Sec. 1065.308: Continuous Upon initial installation, after system
analyzer system response and reconfiguration, and after major
recording. maintenance.
Sec. 1065.309: Continuous Upon initial installation, after system
analyzer uniform response. reconfiguration, and after major
maintenance.
Sec. 1065.310: torque...... Upon initial installation and after major
maintenance.
Sec. 1065.315: pressure, Upon initial installation and after major
temperature, dewpoint. maintenance.
Sec. 1065.320: fuel flow... Upon initial installation and after major
maintenance.
Sec. 1065.325: intake flow. Upon initial installation and after major
maintenance.
Sec. 1065.330: exhaust flow Upon initial installation and after major
maintenance.
Sec. 1065.340: diluted Upon initial installation and after major
exhaust flow (CVS). maintenance.
Sec. 1065.341: CVS and Upon initial installation, within 35 days
batch sampler verification. before testing, and after major
maintenance.
Sec. 1065.345: vacuum leak. Before each laboratory test according to
subpart F of this part and before each
field test according to subpart J of
this part.
Sec. 1065.350: CO2 NDIRH2O Upon initial installation and after major
interference. maintenance.
Sec. 1065.355: CO NDIRCO2 Upon initial installation and after major
and H2Ointerference. maintenance.
Sec. 1065.360: FID Calibrate, optimize, and determine CH4
optimization, etc.. response: upon initial installation and
after major maintenance.
Verify CH4 response: upon initial
installation, within 185 days before
testing, and after major maintenance.
Sec. 1065.362: raw Upon initial installation, after FID
exhaustFID O2 interference. optimization according to Sec.
1065.360, and after major maintenance.
Sec. 1065.365:nonmethane Upon initial installation, within 185
cutter penetration. days before testing, and after major
maintenance.
Sec. 1065.370: CLD CO2 and Upon initial installation and after major
H2O quench. maintenance.
Sec. 1065.372: NDUV HC and Upon initial installation and after major
H2O interference. maintenance.
Sec. 1065.376: chiller NO2 Upon initial installation and after major
penetration. maintenance.
Sec. 1065.378: NO2-to-NO Upon initial installation, within 35 days
converter conversion. before testing, and after major
maintenance.
Sec. 1065.390: PM balance Independent verification: upon initial
and weighing. installation, within 370 days before
testing, and after major maintenance.
Zero, span, and reference sample
verifications: within 12 hours of
weighing, and after major maintenance.
Sec. 1065.395: Inertial PM Independent verification: upon initial
balance and weighing. installation, within 370 days before
testing, and after major maintenance.

[[Page 40544]]

Other verifications: upon initial
installation and after major
maintenance.
------------------------------------------------------------------------
\a\ Perform calibrations and verifications more frequently, according to
measurement system manufacturer instructions and good engineering
judgment.

Sec. 1065.305 Verifications for accuracy, repeatability, and noise.

(a) This section describes how to determine the accuracy,
repeatability, and noise of an instrument. Table 1 of Sec. 1065.205
specifies recommended values for individual instruments.
(b) We do not require you to verify instrument accuracy,
repeatability, or noise.
However, it may be useful to consider these verifications to define
a specification for a new instrument, to verify the performance of a
new instrument upon delivery, or to troubleshoot an existing instrument.
(c) In this section we use the letter ``y'' to denote a generic
measured quantity, the superscript over-bar to denote an arithmetic
mean (such as y), and the subscript ``_ref'' to denote the
reference quantity being measured.
(d) Conduct these verifications as follows:
(1) Prepare an instrument so it operates at its specified
temperatures, pressures, and flows. Perform any instrument
linearization or calibration procedures prescribed by the instrument
manufacturer.
(2) Zero the instrument as you would before an emission test by
introducing a zero signal. Depending on the instrument, this may be a
zero-concentration gas, a reference signal, a set of reference
thermodynamic conditions, or some combination of these. For gas
analyzers, use a zero gas that meets the specifications of Sec. 1065.750.
(3) Span the instrument as you would before an emission test by
introducing a span signal. Depending on the instrument, this may be a
span-concentration gas, a reference signal, a set of reference
thermodynamic conditions, or some combination of these. For gas
analyzers, use a span gas that meets the specifications of Sec. 1065.750.
(4) Use the instrument to quantify a NIST-traceable reference
quantity, y_ref . For gas analyzers the reference gas must
meet the specifications of Sec. 1065.750. Select a reference quantity
near the mean value expected during testing. For all gas analyzers, use
a quantity near the flow-weighted mean concentration expected at the
standard or expected during testing, whichever is greater. For a noise
verfication, use the same zero gas from paragraph (e) of this section
as the reference quantity. In all cases, allow time for the instrument
to stabilize while it measures the reference quantity. Stabilization
time may include time to purge an instrument and time to account for
its response.
(5) Sample and record values for 30 seconds, record the arithmetic
mean, y_i, and record the standard deviation,
[sigma]_i, of the recorded values. Refer to Sec. 1065.602
for an example of calculating arithmetic mean and standard deviation.
(6) Also, if the reference quantity is not absolutely constant,
which might be the case with a reference flow, sample and record values
of y_refi for 30 seconds and record the arithmetic mean of
the values, y_ref. Refer to Sec. 1065.602 for an example of
calculating arithmetic mean.
(7) Subtract the reference value, y_ref (or
y_ref), from the arithmetic mean, y_i. Record this
value as the error, [egr]_i.
(8) Repeat the steps specified in paragraphs (d)(2) through (6) of
this section until you have ten arithmetic means (y₁,
y₂, y_i, * * * y₁₀), ten standard
deviations, ([sigma]₁, [sigma]₂,
[sigma]_i,* * *[sigma]₁₀), and ten errors
([egr]₁, [egr]₂, [egr]_i, * * *
[egr]₁₀).
(9) Use the following values to quantify your measurements:
(i) Accuracy. Instrument accuracy is the absolute difference
between the reference quantity, y_ref (or y_ref),
and the arithmetic mean of the ten y_i, y values. Refer to
the example of an accuracy calculation in Sec. 1065.602. We recommend
that instrument accuracy be within the specifications in Table 1 of
Sec. 1065.205.
(ii) Repeatability. Repeatability is two times the standard
deviation of the ten errors (that is, repeatability = 2 [middot]
[sigma][egr]). Refer to the example of a standard-deviation calculation
in Sec. 1065.602. We recommend that instrument repeatability be within
the specifications in Table 1 of Sec. 1065.205.
(iii) Noise. Noise is two times the root-mean-square of the ten
standard deviations (that is, noise = 2 [middot]
rms[sigma]) when the
reference signal is a zero-quantity signal. Refer to the example of a
root-mean-square calculation in Sec. 1065.602. We recommend that
instrument noise be within the specifications in Table 1 of Sec.
1065.205. Use this value in the noise correction specified in Sec.
1065.657.
(10) You may use a measurement instrument that does not meet the
accuracy, repeatability, or noise specifications in Table 1 of Sec.
1065.205, as long as you meet the following criteria:
(i) Your measurement systems meet all the other required
calibration, verification, and validation specifications in subparts D,
F, and J of this part, as applicable.
(ii) The measurement deficiency does not adversely affect your
ability to demonstrate compliance with the applicable standards.

Sec. 1065.307 Linearity verification.

(a) Scope and frequency. Perform a linearity verification on each
measurement system listed in Table 1 of this section at least as
frequently as indicated in the table, consistent with measurement
system manufacturer recommendations and good engineering judgment. Note
that this linearity verification may replace requirements we previously
referred to as ``calibrations''. The intent of a linearity verification
is to determine that a measurement system responds proportionally over
the measurement range of interest. A linearity verification generally
consists of introducing a series of at least 10 reference values to a
measurement system. The measurement system quantifies each reference
value. The measured values are then collectively compared to the
reference values by using a least squares linear regression and the
linearity criteria specified in Table 1 of this section.
(b) Performance requirements. If a measurement system does not meet
the applicable linearity criteria in Table 1 of this section, correct
the deficiency by re-calibrating, servicing, or replacing components as
needed. Before you may use a measurement system that does not meet
linearity criteria, you must demonstrate to us that the deficiency does
not adversely affect your ability to demonstrate compliance with the
applicable standards.
(c) Procedure. Use the following linearity verification protocol,
or use good engineering judgment to develop a different protocol that
satisfies the

[[Page 40545]]

intent of this section, as described in paragraph (a) of this section:
(1) In this paragraph (c), we use the letter ``y'' to denote a
generic measured quantity, the superscript over-bar to denote an
arithmetic mean (such as y), and the subscript ``_ref'' to
denote the known or reference quantity being measured.
(2) Operate a measurement system at its specified temperatures,
pressures, and flows. This may include any specified adjustment or
periodic calibration of the measurement system.
(3) Zero the instrument as you would before an emission test by
introducing a zero signal. Depending on the instrument, this may be a
zero-concentration gas, a reference signal, a set of reference
thermodynamic conditions, or some combination of these. For gas
analyzers, use a zero gas that meets the specifications of Sec.
1065.750 and introduce it directly at the analyzer port.
(4) Span the instrument as you would before an emission test by
introducing a span signal. Depending on the instrument, this may be a
span-concentration gas, a reference signal, a set of reference
thermodynamic conditions, or some combination of these. For gas
analyzers, use a span gas that meets the specifications of Sec.
1065.750 and introduce it directly at the analyzer port.
(5) After spanning the instrument, check zero with the same signal
you used in paragraph (c)(3) of this section. Based on the zero
reading, use good engineering judgment to determine whether or not to
rezero and or re-span the instrument before proceeding to the next step.
(6) Use instrument manufacturer recommendations and good
engineering judgment to select at least 10 reference values,
y_refi, that are within the range from zero to the highest
values expected during emission testing. We recommend selecting a zero
reference signal as one of the reference values of the linearity
verification.
(7) Use instrument manufacturer recommendations and good
engineering judgment to select the order in which you will introduce
the series of reference values. For example you may select the
reference values randomly to avoid correlation with previous
measurements, you may select reference values in ascending or
descending order to avoid long settling times of reference signals, or
as another example you may select values to ascend and then descend
which might incorporate the effects of any instrument hysteresis into
the linearity verification.
(8) Generate reference quantities as described in paragraph (d) of
this section. For gas analyzers, use gas concentrations known to be
within the specifications of Sec. 1065.750 and introduce them directly
at the analyzer port.
(9) Introduce a reference signal to the measurement instrument.
(10) Allow time for the instrument to stabilize while it measures
the reference value. Stabilization time may include time to purge an
instrument and time to account for its response.
(11) At a recording frequency of at least f Hz, specified in Table
1 of Sec. 1065.205, measure the reference value for 30 seconds and
record the arithmetic mean of the recorded values, y_i. Refer
to Sec. 1065.602 for an example of calculating an arithmetic mean.
(12) Repeat steps in paragraphs (c)(9) through (11) of this section
until all reference quantities are measured.
(13) Use the arithmetic means y_i, and reference values,
y_refi , to calculate least-squares linear regression
parameters and statistical values to compare to the minimum performance
criteria specified in Table 1 of this section. Use the calculations
described in Sec. 1065.602.
(d) Reference signals. This paragraph (d) describes recommended
methods for generating reference values for the linearity-verification
protocol in paragraph (c) of this section. Use reference values that
simulate actual values, or introduce an actual value and measure it
with a reference-measurement system. In the latter case, the reference
value is the value reported by the reference-measurement system.
Reference values and reference-measurement systems must be NIST-
traceable. We recommend using calibration reference quantities that are
NIST-traceable within 0.5% uncertainty, if not specified otherwise in
other sections of this part 1065. Use the following recommended methods
to generate reference values or use good engineering judgment to select
a different reference:
(1) Engine speed. Run the engine or dynamometer at a series of
steady-state speeds and use a strobe, a photo tachometer, or a laser
tachometer to record reference speeds.
(2) Engine torque. Use a series of calibration weights and a
calibration lever arm to simulate engine torque. You may instead use
the engine or dynamometer itself to generate a nominal torque that is
measured by a reference load cell or proving ring in series with the
torque-measurement system. In this case use the reference load cell
measurement as the reference value. Refer to Sec. 1065.310 for a
torque-calibration procedure similar to the linearity verification in
this section.
(3) Electrical work. Use a controlled source of current and a watt-
hour standard reference meter. Complete calibration systems that
contain a current source and a reference watt-hour meter are commonly
used in the electrical power distribution industry and are therefore
commercially available.
(4) Fuel rate. Operate the engine at a series of constant fuel-flow
rates or re-circulate fuel back to a tank through the fuel flow meter
at different flow rates. Use a gravimetric reference measurement (such
as a scale, balance, or mass comparator) at the inlet to the fuel-
measurement system. Use a stopwatch or timer to measure the time
intervals over which reference masses of fuel are introduced to the
fuel measurement system. The reference fuel mass divided by the time
interval is the reference fuel flow rate.
(5) Flow rates--inlet air, dilution air, diluted exhaust, raw
exhaust, or sample flow. Use a reference flow meter with a blower or
pump to simulate flow rates. Use a restrictor, diverter valve, a
variable-speed blower or a variable-speed pump to control the range of
flow rates. Use the reference meter's response as the reference values.
(i) Reference flow meters. Because the flow range requirements for
these various flows are large, we allow a variety of reference meters.
For example, for diluted exhaust flow for a full-flow dilution system,
we recommend a reference subsonic venturi flow meter with a restrictor
valve and a blower to simulate flow rates. For inlet air, dilution air,
diluted exhaust for partial-flow dilution, raw exhaust, or sample flow,
we allow reference meters such as critical flow orifices, critical flow
venturis, laminar flow elements, master mass flow standards, or Roots
meters. Make sure the reference meter is calibrated by the flow-meter
manufacturer and its calibration is NIST-traceable. If you use the
difference of two flow measurements to determine a net flow rate, you
may use one of the measurements as a reference for the other.
(ii) Reference flow values. Because the reference flow is not
absolutely constant, sample and record values of n_refi for
30 seconds and use the arithmetic mean of the values, n_ref,
as the reference value. Refer to Sec. 1065.602 for an example of
calculating arithmetic mean.
(6) Gas division. Use one of the two reference signals: (i) At the
outlet of the gas-division system, connect a gas analyzer that meets
the linearity

[[Page 40546]]

verification described in this section and has not been linearized with
the gas divider being verified. For example, verify the linearity of an
analyzer using a series of reference analytical gases directly from
compressed gas cylinders that meet the specifications of Sec.
1065.750. We recommend using a FID analyzer or a PMD/MPD O₂
analyzer because of their inherent linearity. Operate this analyzer
consistent with how you would operate it during an emission test.
Connect a span gas to the gas-divider inlet. Use the gas-division
system to divide the span gas with purified air or nitrogen. Select gas
divisions that you typically use. Use a selected gas division as the
measured value. Use the analyzer response divided by the span gas
concentration as the reference gas-division value. Because the
instrument response is not absolutely constant, sample and record
values of x_refi for 30 seconds and use the arithmetic mean
of the values x_refi, as the reference value. Refer to Sec.
1065.602 for an example of calculating arithmetic mean.
(ii) Using good engineering judgment and gas divider manufacturer
recommendations, use one or more reference flow meters to verify the
measured flow rates of the gas divider.
(7) Continuous constituent concentration. For reference values, use
a series of gas cylinders of known gas concentration or use a gas-
division system that is known to be linear with a span gas. Gas
cylinders, gas-division systems, and span gases that you use for
reference values must meet the specifications of Sec. 1065.750.

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Sec. 1065.308 Continuous gas analyzer system-response and updating-
recording verification.

(a) Scope and frequency. Perform this verification after installing
or replacing a gas analyzer that you use for continuous sampling. Also
perform this verification if you reconfigure your system in a way that
would change system response. For example, perform this verification if
you add a significant volume to the transfer lines by increasing their
length or adding a filter; or if you change the frequency at which you
sample and record gas-analyzer concentrations.
(b) Measurement principles. This test verifies that the updating
and recording frequencies match the overall system response to a rapid
change in the value of concentrations at the sample probe. Gas analyzer
systems must be optimized such that their overall response to a rapid
change in concentration is updated and recorded at an appropriate
frequency to prevent loss of information.
(c) System requirements. To demonstrate acceptable updating and
recording with respect to the system's overall response, use good
engineering judgment to select one of the following criteria that your
system must meet:
(1) The product of the mean rise time and the frequency at which
the system records an updated concentration must be at least 5, and the
product of the mean fall time and the frequency at

[[Page 40548]]

which the system records an updated concentration must be at least 5.
This criteria makes no assumption regarding the frequency content of
changes in emission concentrations during emission testing; therefore,
it is valid for any testing.
(2) The frequency at which the system records an updated
concentration must be at least 5 Hz. This criteria assumes that the
frequency content of significant changes in emission concentrations
during emission testing do not exceed 1 Hz.
(3) You may use other criteria if we approve the criteria in
advance.
(4) For PEMS, you do not have to meet this criteria if your PEMS
meets the overall PEMS check in Sec. 1065.920.
(d) Procedure. Use the following procedure to verify the response
of a continuous gas analyzer system:
(1) Instrument setup. Follow the analyzer system manufacturer's
start-up and operating instructions. Adjust the system as needed to
optimize performance.
(2) Equipment setup. Using minimal gas transfer line lengths
between all connections, connect a zero-air source to one inlet of a
fast-acting 3-way valve (2 inlets, 1 outlet). Using a gas divider,
equally blend an NO-CO-CO₂-C₃H₈-
CH₄ (balance N₂) span gas with a span gas of
NO₂. Connect the gas divider outlet to the other inlet of
the 3-way valve. Connect the valve outlet to an overflow at the gas
analyzer system's probe or to an overflow fitting between the probe and
transfer line to all the analyzers being verified.
(3) Data collection. (i) Switch the valve to flow zero gas.
(ii) Allow for stabilization, accounting for transport delays and
the slowest instrument's full response.
(iii) Start recording data at the frequency used during emission
testing. Each recorded value must be a unique updated concentration
measured by the analyzer; you may not use interpolation to increase the
number of recorded values.
(iv) Switch the valve to flow the blended span gases.
(v) Allow for transport delays and the slowest instrument's full
response.
(vi) Repeat the steps in paragraphs (d)(3)(i) through (v) of this
section to record seven full cycles, ending with zero gas flowing to
the analyzers.
(vii) Stop recording.
(e) Performance evaluation. (1) If you chose to demonstrate
compliance with paragraph
(c)(1) of this section, use the data from paragraph (d)(3) of this
section to calculate the mean rise time, T_10-90, and mean
fall time, T_90-10, for each of the analyzers. Multiply these
times (in seconds) by their respective recording frequencies in Hertz
(1/second). The value for each result must be at least 5. If the value
is less than 5, increase the recording frequency or adjust the flows or
design of the sampling system to increase the rise time and fall time
as needed. You may also configure digital filters to increase rise and
fall times.
(2) If a measurement system fails the criterion in paragraph (e)(1)
of this section, ensure that signals from the system are updated and
recorded at a frequency of at least 5 Hz.
(3) If a measurement system fails the criteria in paragraphs (e)(1)
and (2) of this section, you may use the continuous analyzer system
only if the deficiency does not adversely affect your ability to show
compliance with the applicable standards.

Sec. 1065.309 Continuous gas analyzer uniform response verification.

(a) Scope and frequency. If you use more than one continuous gas
analyzer to quantify a gaseous constituent, you must perform this
verification. For example, if you determine NMHC as the difference
between continuous THC and CH₄ measurements, you must
perform this verification on your NMHC measurement system. As another
example if you determine NO_X as the sum of separate
continuous measurements of NO and NO₂, you must perform this
verification on your NO_X measurement system. Also, you must
perform this verification if you use one continuous analyzer to apply
an interference compensation algorithm to another continuous gas
analyzer. Perform this verification after initial installation or major
maintenance. Also perform this verification if you reconfigure your
system in a way that would change system response. For example, perform
this verification if you add a significant volume to the transfer lines
by increasing their length or by adding a filter; or if you change the
frequency at which you sample and record gas-analyzer concentrations.
(b) Measurement principles. This procedure verifies the time-
alignment and uniform response of combined continuous gas measurements.
(c) System requirements. Demonstrate that combined continuous
concentration measurements have a uniform rise and fall during a
simultaneous to a step change in both concentrations. During a system
response to a rapid change in multiple gas concentrations, demonstrate
that the t₅₀ times of all combined analyzers all occur at
the same recorded second of data or between the same two recorded
seconds of data.
(d) Procedure. Use the following procedure to verify the response
of a continuous gas analyzer system:
(1) Instrument setup. Follow the analyzer system manufacturer's
start-up and operating instructions. Adjust the system as needed to
optimize performance.
(2) Equipment setup. Using minimal gas transfer line lengths
between all connections, connect a zero-air source to the inlet of a
100 [deg]C heated line. Connect the heated line outlet to one inlet of
a 100 [deg]C heated fast-acting 3-way valve (2 inlets, 1 outlet). Using
a gas divider, equally blend an NO-CO-CO₂-
C₃H₈-CH₄ (balance N₂) span
gas with a span gas of NO₂ (balance N₂). Connect
the gas divider outlet to the inlet of a 50 [deg]C heated line. Connect
the heated line outlet to the inlet of a 50 [deg]C gas bubbler filled
with distilled water. Connect the bubbler outlet to another heated line
at 100 [deg]C. Connect the outlet of the 100 [deg]C line to the other
inlet of the 3-way valve. Connect the valve outlet to an overflow at
the gas analyzer system's probe or to an overflow fitting between the
probe and transfer line to all the analyzers being verified.
(3) Data collection. (i) Switch the valve to flow zero gas.
(ii) Allow for stabilization, accounting for transport delays and
the slowest instrument's full response.
(iii) Start recording data at the frequency used during emission
testing.
(iv) Switch the valve to flow span gas.
(v) Allow for transport delays and the slowest instrument's full
response.
(vi) Repeat the steps in paragraphs (d)(3)(i) through (v) of this
section to record seven full cycles, ending with zero gas flowing to
the analyzers.
(vii) Stop recording.
(e) Performance evaluations. Perform the following evaluations:
(1) Uniform response evaluation. (i) Calculate the mean rise time,
t_10-90, mean fall time, t_90-10 for each analyzer.
(ii) Determine the maximum mean rise and fall times for the slowest
responding analyzer in each combination of continuous analyzer signals
that you use to determine a single emission concentration.
(iii) If the maximum rise time or fall time is greater than one
second, verify that all other gas analyzers combined with it have mean
rise and fall times of at least 75% of that analyzer's response.
(iv) If any analyzer has shorter rise or fall times, disperse that
signal so that it better matches the rise and fall times of the slowest
signal with which it is combined. We recommend that you perform
dispersion using SAE 2001-01-

[[Page 40549]]

3536 (incorporated by reference in Sec. 1065.1010) as a guide.
(v) Repeat this verification after optimizing your systems to
ensure that you dispersed signals correctly. If after repeated attempts
at dispersing signals your system still fails this verification, you
may use the continuous analyzer system if the deficiency does not
adversely affect your ability to show compliance with the applicable
standards.
(2) Time alignment evaluation. (i) After all signals are adjusted
to meet the uniform response evaluation, determine the second at
which--or the two seconds between which--each analyzer crossed the
midpoint of its response, t₅₀.
(ii) Verify that all combined gas analyzer signals are time-aligned
such that all of their t₅₀ times occurred at the same second
or between the same two seconds in the recorded data.
(iii) If your system fails to meet this criterion, you may change
the time alignment of your system and retest the system completely. If
after changing the time alignment of your system, some of the
t₅₀ times still are not aligned, take corrective action by
dispersing analyzer signals that have the shortest rise and fall times.
(iv) If some t50 times are still not aligned after repeated
attempts at dispersion and time alignment, you may use the continuous
analyzer system if the deficiency does not adversely affect your
ability to show compliance with the applicable standards.

Measurement of Engine Parameters and Ambient Conditions

Sec. 1065.310 Torque calibration.

(a) Scope and frequency. Calibrate all torque-measurement systems
including dynamometer torque measurement transducers and systems upon
initial installation and after major maintenance. Use good engineering
judgment to repeat the calibration. Follow the torque transducer
manufacturer's instructions for linearizing your torque sensor's
output. We recommend that you calibrate the torque-measurement system
with a reference force and a lever arm.
(b) Recommended procedure. (1) Reference force quantification. Use
either a set of dead-weights or a reference meter such as strain gage
or a proving ring to quantify the reference force, NIST-traceable
within ±0.5% uncertainty.
(2) Lever-arm length quantification. Quantify the lever arm length,
NIST-traceable within ±0.5% uncertainty. The lever arm's
length must be measured from the centerline of the dynamometer to the
point at which the reference force is measured. The lever arm must be
perpendicular to gravity (i.e., horizontal), and it must be
perpendicular to the dynamometer's rotational axis. Balance the lever
arm's torque or quantify its net hanging torque, NIST-traceable within
±1% uncertainty, and account for it as part of the reference
torque.
(c) Dead-weight calibration. This technique applies a known force
by hanging known weights at a known distance along a lever arm. Make
sure the weights' lever arm is perpendicular to gravity (i.e.,
horizontal) and perpendicular to the dynamometer's rotational axis.
Apply at least six calibration-weight combinations for each applicable
torque-measuring range, spacing the weight quantities about equally
over the range. Oscillate or rotate the dynamometer during calibration
to reduce frictional static hysteresis. Determine each weight's force
by multiplying its NIST-traceable mass by the local acceleration of
Earth's gravity (using this equation: force = mass [middot]
acceleration). The local acceleration of gravity, a_g, at
your latitude, longitude, and elevation may be determined by entering
position and elevation data into the U.S. National Oceanographic and
Atmospheric Administration's surface gravity prediction Web site at
http://www.ngs.noaa.gov/cgi-bin/grav_pdx.prl. If this Web site is
unavailable, you may use the equation in Sec. 1065.630, which returns
the local acceleration of gravity based on a given latitude. In this
case, calculate the reference torque as the weights' reference force
multiplied by the lever arm reference length (using this equation:
torque = force [middot]
lever arm length).
(d) Strain gage or proving ring calibration. This technique applies
force either by hanging weights on a lever arm (these weights and their
lever arm length are not used) or by operating the dynamometer at
different torques. Apply at least six force combinations for each
applicable torque-measuring range, spacing the force quantities about
equally over the range. Oscillate or rotate the dynamometer during
calibration to reduce frictional static hysteresis. In this case, the
reference torque is determined by multiplying the reference meter force
output by its effective lever-arm length, which you measure from the
point where the force measurement is made to the dynamometer's
rotational axis. Make sure you measure this length perpendicular to
gravity (i.e., horizontal) and perpendicular to the dynamometer's
rotational axis.

Sec. 1065.315 Pressure, temperature, and dewpoint calibration.

(a) Calibrate instruments for measuring pressure, temperature, and
dewpoint upon initial installation. Follow the instrument
manufacturer's instructions and use good engineering judgment to repeat
the calibration, as follows:
(1) Pressure. We recommend temperature-compensated, digital-
pneumatic, or deadweight pressure calibrators, with data-logging
capabilities to minimize transcription errors. We recommend using
calibration reference quantities that are NIST-traceable within 0.5%
uncertainty.
(2) Temperature. We recommend digital dry-block or stirred-liquid
temperature calibrators, with datalogging capabilities to minimize
transcription errors. We recommend using calibration reference
quantities that are NIST-traceable within 0.5% uncertainty.
(3) Dewpoint. We recommend a minimum of three different
temperature-equilibrated and temperature-monitored calibration salt
solutions in containers that seal completely around the dewpoint
sensor. We recommend using calibration reference quantities that are
NIST-traceable within 0.5% uncertainty.
(b) You may remove system components for off-site calibration. We
recommend specifying calibration reference quantities that are NIST-
traceable within 0.5% uncertainty.

Flow-Related Measurements

Sec. 1065.320 Fuel-flow calibration.

(a) Calibrate fuel-flow meters upon initial installation. Follow
the instrument manufacturer's instructions and use good engineering
judgment to repeat the calibration.
(b) You may also develop a procedure based on a chemical balance of
carbon or oxygen in engine exhaust.
(c) You may remove system components for off-site calibration. When
installing a flow meter with an off-site calibration, we recommend that
you consider the effects of the tubing configuration upstream and
downstream of the flow meter. We recommend specifying calibration
reference quantities that are NIST-traceable within 0.5% uncertainty.

Sec. 1065.325 Intake-flow calibration.

(a) Calibrate intake-air flow meters upon initial installation.
Follow the instrument manufacturer's instructions and use good
engineering judgment to repeat the calibration. We recommend using a
calibration subsonic venturi, ultrasonic flow meter or laminar flow

[[Page 40550]]

element. We recommend using calibration reference quantities that are
NIST-traceable within 0.5% uncertainty.
(b) You may remove system components for off-site calibration. When
installing a flow meter with an off-site calibration, we recommend that
you consider the effects of the tubing configuration upstream and
downstream of the flow meter. We recommend specifying calibration
reference quantities that are NIST-traceable within 0.5% uncertainty.
(c) If you use a subsonic venturi or ultrasonic flow meter for
intake flow measurement, we recommend that you calibrate it as
described in Sec. 1065.340.

Sec. 1065.330 Exhaust-flow calibration.

(a) Calibrate exhaust-flow meters upon initial installation. Follow
the instrument manufacturer's instructions and use good engineering
judgment to repeat the calibration. We recommend that you use a
calibration subsonic venturi or ultrasonic flow meter and simulate
exhaust temperatures by incorporating a heat exchanger between the
calibration meter and the exhaust-flow meter. If you can demonstrate
that the flow meter to be calibrated is insensitive to exhaust
temperatures, you may use other reference meters such as laminar flow
elements, which are not commonly designed to withstand typical raw
exhaust temperatures. We recommend using calibration reference
quantities that are NIST-traceable within 0.5% uncertainty.
(b) You may remove system components for off-site calibration. When
installing a flow meter with an off-site calibration, we recommend that
you consider the effects of the tubing configuration upstream and
downstream of the flow meter. We recommend specifying calibration
reference quantities that are NIST-traceable within 0.5% uncertainty.
(c) If you use a subsonic venturi or ultrasonic flow meter for raw
exhaust flow measurement, we recommend that you calibrate it as
described in Sec. 1065.340.

Sec. 1065.340 Diluted exhaust flow (CVS) calibration.

(a) Overview. This section describes how to calibrate flow meters
for diluted exhaust constant-volume sampling (CVS) systems.
(b) Scope and frequency. Perform this calibration while the flow
meter is installed in its permanent position. Perform this calibration
after you change any part of the flow configuration upstream or
downstream of the flow meter that may affect the flow-meter
calibration. Perform this calibration upon initial CVS installation and
whenever corrective action does not resolve a failure to meet the
diluted exhaust flow verification (i.e., propane check) in Sec. 1065.341.
(c) Reference flow meter. Calibrate a CVS flow meter using a
reference flow meter such as a subsonic venturi flow meter, a long-
radius ASME/NIST flow nozzle, a smooth approach orifice, a laminar flow
element, a set of critical flow venturis, or an ultrasonic flow meter.
Use a reference flow meter that reports quantities that are NIST-
traceable within ±1% uncertainty. Use this reference flow
meter's response to flow as the reference value for CVS flow-meter
calibration.
(d) Configuration. Do not use an upstream screen or other
restriction that could affect the flow ahead of the reference flow
meter, unless the flow meter has been calibrated with such a restriction.
(e) PDP calibration. Calibrate a positive-displacement pump (PDP)
to determine a flow-versus-PDP speed equation that accounts for flow
leakage across sealing surfaces in the PDP as a function of PDP inlet
pressure. Determine unique equation coefficients for each speed at
which you operate the PDP. Calibrate a PDP flow meter as follows:
(1) Connect the system as shown in Figure 1 of this section.
(2) Leaks between the calibration flow meter and the PDP must be
less than 0.3% of the total flow at the lowest calibrated flow point;
for example, at the highest restriction and lowest PDP-speed point.
(3) While the PDP operates, maintain a constant temperature at the
PDP inlet within ±2% of the mean absolute inlet temperature,
T_in.
(4) Set the PDP speed to the first speed point at which you intend
to calibrate.
(5) Set the variable restrictor to its wide-open position.
(6) Operate the PDP for at least 3 min to stabilize the system.
Continue operating the PDP and record the mean values of at least 30
seconds of sampled data of each of the following quantities:
(i) The mean flow rate of the reference flow meter,
n_ref. This may include several measurements of different
quantities, such as reference meter pressures and temperatures, for
calculating n_ref.
(ii) The mean temperature at the PDP inlet, T _in.
(iii) The mean static absolute pressure at the PDP inlet, P _in.
(iv) The mean static absolute pressure at the PDP outlet, P _out.
(v) The mean PDP speed, f _nPDP.
(7) Incrementally close the restrictor valve to decrease the
absolute pressure at the inlet to the PDP, P _in.
(8) Repeat the steps in paragraphs (e)(6) and (7) of this section
to record data at a minimum of six restrictor positions reflecting the
full range of possible in-use pressures at the PDP inlet.
(9) Calibrate the PDP by using the collected data and the equations
in Sec. 1065.640.
(10) Repeat the steps in paragraphs (e)(6) through (9) of this
section for each speed at which you operate the PDP.
(11) Use the equations in Sec. 1065.642 to determine the PDP flow
equation for emission testing.
(12) Verify the calibration by performing a CVS verification (i.e.,
propane check) as described in Sec. 1065.341.
(13) Do not use the PDP below the lowest inlet pressure tested
during calibration.
(f) CFV calibration. Calibrate a critical-flow venturi (CFV) to
verify its discharge coefficient, C_d, at the lowest expected
static differential pressure between the CFV inlet and outlet.
Calibrate a CFV flow meter as follows:
(1) Connect the system as shown in Figure 1 of this section.
(2) Start the blower downstream of the CFV.
(3) While the CFV operates, maintain a constant temperature at the
CFV inlet within ±2% of the mean absolute inlet temperature,
T _in.
(4) Leaks between the calibration flow meter and the CFV must be
less than 0.3 % of the total flow at the highest restriction.
(5) Set the variable restrictor to its wide-open position.
(6) Operate the CFV for at least 3 min to stabilize the system.
Continue operating the CFV and record the mean values of at least 30
seconds of sampled data of each of the following quantities:
(i) The mean flow rate of the reference flow meter,
n_ref. This may include several measurements of different
quantities, such as reference meter pressures and temperatures, for
calculating n_ref.
(ii) Optionally, the mean dewpoint of the calibration air, T
_dew. See Sec. 1065.640 for permissible assumptions.
(iii) The mean temperature at the venturi inlet, T _in.
(iv) The mean static absolute pressure at the venturi inlet, P
_in.
(v) The mean static differential pressure between the CFV inlet and
the CFV outlet, [Delta]P _CFV.
(7) Incrementally close the restrictor valve to decrease the
absolute pressure at the inlet to the CFV, _Pin.

[[Page 40551]]

(8) Repeat the steps in paragraphs (f)(6) and (7) of this section
to record mean data at a minimum of ten restrictor positions, such that
you test the fullest practical range of [Delta]P _CFV
expected during testing. We do not require that you remove calibration
components or CVS components to calibrate at the lowest possible
restrictions.
(9) Determine C_d and the lowest allowable [Delta]P
_CFV as described in Sec. 1065.640.
(10) Use C_d to determine CFV flow during an emission
test. Do not use the CFV below the lowest allowed [Delta]P
_CFV, as determined in Sec. 1065.640.
(11) Verify the calibration by performing a CVS verification (i.e.,
propane check) as described in Sec. 1065.341.
(12) If your CVS is configured to operate more than one CFV at a
time in parallel, calibrate your CVS by one of the following:
(i) Calibrate every combination of CFVs according to this section
and Sec. 1065.640. Refer to Sec. 1065.642 for instructions on
calculating flow rates for this option.
(ii) Calibrate each CFV according to this section and Sec.
1065.640. Refer to Sec. 1065.642 for instructions on calculating flow
rates for this option.
(g) SSV calibration. Calibrate a subsonic venturi (SSV) to
determine its calibration coefficient, C_d , for the expected
range of inlet pressures. Calibrate an SSV flow meter as follows:
(1) Connect the system as shown in Figure 1 of this section.
(2) Start the blower downstream of the SSV.
(3) Leaks between the calibration flow meter and the SSV must be
less than 0.3 % of the total flow at the highest restriction.
(4) While the SSV operates, maintain a constant temperature at the
SSV inlet within ±2 % of the mean absolute inlet temperature.
(5) Set the variable restrictor or variable-speed blower to a flow
rate greater than the greatest flow rate expected during testing. You
may not extrapolate flow rates beyond calibrated values, so we
recommend that you make sure the Reynolds number, Re#, at the
SSV throat at the greatest calibrated flow rate is greater than the
maximum Re# expected during testing.
(6) Operate the SSV for at least 3 min to stabilize the system.
Continue operating the SSV and record the mean of at least 30 seconds
of sampled data of each of the following quantities:
(i) The mean flow rate of the reference flow meter,
n_ref. This may include several measurements of different
quantities, such as reference meter pressures and temperatures, for
caculating n_ref.
(ii) Optionally, the mean dewpoint of the calibration air, T dew.
See Sec. 1065.640 for permissible assumptions.
(iii) The mean temperature at the venturi inlet, T in .
(iv) The mean static absolute pressure at the venturi inlet, P in.
(v) Static differential pressure between the static pressure at the
venturi inlet and the static pressure at the venturi throat, [Delta]
P SSV.
(7) Incrementally close the restrictor valve or decrease the blower
speed to decrease the flow rate.
(8) Repeat the steps in paragraphs (g)(6) and (7) of this section
to record data at a minimum of ten flow rates.
(9) Determine a functional form of C_d versus Re#
by using the collected data and the equations in Sec. 1065.640.
(10) Verify the calibration by performing a CVS verification (i.e.,
propane check) as described in Sec. 1065.341 using the new
C_d versus Re# equation.
(11) Use the SSV only between the minimum and maximum calibrated
flow rates.
(12) Use the equations in Sec. 1065.642 to determine SSV flow
during a test.
(h) Ultrasonic flow meter calibration. [Reserved]

BILLING CODE 6560-50-P

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BILLING CODE 6560-50-C

Sec. 1065.341 CVS and batch sampler verification (propane check).

(a) A propane check serves as a CVS verification to determine if
there is a discrepancy in measured values of diluted exhaust flow. A
propane check also serves as a batch-sampler verification to determine
if there is a discrepancy in a batch sampling system that extracts a
sample from a CVS, as described in paragraph (g) of this section. Using
good engineering judgment and safe practices, this check may be
performed using a gas other than propane, such as CO2 or CO. A failed
propane check might indicate one or more problems that may require
corrective action, as follows:
(1) Incorrect analyzer calibration. Re-calibrate, repair, or
replace the FID analyzer.
(2) Leaks. Inspect CVS tunnel, connections, fasteners, and HC
sampling system, and repair or replace components.
(3) Poor mixing. Perform the verification as described in this
section while traversing a sampling probe across the tunnel's diameter,
vertically and horizontally. If the analyzer response indicates any
deviation exceeding ±2% of the mean measured concentration,
consider operating the CVS at a higher flow rate or installing a mixing
plate or orifice to improve mixing.

[[Page 40553]]

(4) Hydrocarbon contamination in the sample system. Perform the
hydrocarbon-contamination verification as described in Sec. 1065.520.
(5) Change in CVS calibration. Perform an in-situ calibration of
the CVS flow meter as described in Sec. 1065.340.
(6) Other problems with the CVS or sampling verification hardware
or software.
Inspect the CVS system, CVS verification hardware, and software for
discrepancies. (b) A propane check uses either a reference mass or a
reference flow rate of C3H8 as a tracer gas in a CVS. Note that if you
use a reference flow rate, account for any non-ideal gas behavior of
C3H8 in the reference flow meter. Refer to Sec. 1065.640 and Sec.
1065.642, which describe how to calibrate and use certain flow meters.
Do not use any ideal gas assumptions in Sec. 1065.640 and Sec.
1065.642. The propane check compares the calculated mass of injected
C3H8 using HC measurements and CVS flow rate measurements with the
reference value.
(c) Prepare for the propane check as follows:
(1) If you use a reference mass ofC3H8 instead of a reference flow
rate, obtain a cylinder charged with C3H8. Determine the reference
cylinder's mass of C3H8 within ±0.5% of the amount of C3H8
that you expect to use.
(2) Select appropriate flow rates for the CVS andC3H8.
(3) Select aC3H8 injection port in the CVS. Select the port
location to be as close as practical to the location where you
introduce engine exhaust into the CVS. Connect the C3H8 cylinder to the
injection system.
(4) Operate and stabilize the CVS.
(5) Preheat or precool any heat exchangers in the sampling system.
(6) Allow heated and cooled components such as sample lines,
filters, chillers, and pumps to stabilize at operating temperature.
(7) You may purge the HC sampling system during stabilization.
(8) If applicable, perform a vacuum side leak verification of the
HC sampling system as described in Sec. 1065.345.
(9) You may also conduct any other calibrations or verifications on
equipment or analyzers.
(d) Zero, span, and verify contamination of the HC sampling system,
as follows:
(1) Select the lowest HC analyzer range that can measure the C3H8
concentration expected for the CVS and C3H8 flow rates.
(2) Zero the HC analyzer using zero air introduced at the analyzer
port.
(3) Span the HC analyzer using C3H8 span gas introduced at the
analyzer port.
(4) Overflow zero air at the HC probe or into a fitting between the
HC probe and the transfer line.
(5) Measure the stable HC concentration of the HC sampling system
as overflow zero air flows. For batch HC measurement, fill the batch
container (such as a bag) and measure the HC overflow concentration.
(6) If the overflow HC concentration exceeds 2 [mu]mol/mol, do not
proceed until contamination is eliminated. Determine the source of the
contamination and take corrective action, such as cleaning the system
or replacing contaminated portions.
(7) When the overflow HC concentration does not exceed 2 [mu]mol/
mol, record this value as x_HCpre and use it to correct for
HC contamination as described in Sec. 1065.660.
(e) Perform the propane check as follows:
(1) For batch HC sampling, connect clean storage media, such as
evacuated bags.
(2) Operate HC measurement instruments according to the instrument
manufacturer's instructions.
(3) If you will correct for dilution air background concentrations
of HC, measure and record background HC in the dilution air.
(4) Zero any integrating devices.
(5) Begin sampling, and start any flow integrators.
(6) Release the contents of the C3H8 reference cylinder at the rate
you selected. If you use a reference flow rate of C3H8, start
integrating this flow rate.
(7) Continue to release the cylinder's contents until at least
enough C3H8 has been released to ensure accurate quantification of the
reference C3H8 and the measured C3H8.
(8) Shut off the C3H8 reference cylinder and continue sampling
until you have accounted for time delays due to sample transport and
analyzer response.
(9) Stop sampling and stop any integrators.
(f) Perform post-test procedure as follows:
(1) If you used batch sampling, analyze batch samples as soon as
practical.
(2) After analyzing HC, correct for contamination and background.
(3) Calculate total C3H8 mass based on your CVS and HC data as
described in Sec. 1065.650 and Sec. 1065.660, using the molar mass of
C3H8, MC3H8, instead the effective molar mass of HC, M_HC.
(4) If you use a reference mass, determine the cylinder's propane
mass within ±0.5% and determine the C3H8 reference mass by
subtracting the empty cylinder propane mass from the full cylinder
propane mass.
(5) Subtract the reference C3H8 mass from the calculated mass. If
this difference is within ±2.0 % of the reference mass, the
CVS passes this verification. If not, take corrective action as
described in paragraph (a) of this section.
(g) Batch sampler verification. You may repeat the propane check to
verify a batch sampler, such as a PM secondary dilution system.
(1) Configure the HC sampling system to extract a sample near the
location of the batch sampler's storage media (such as a PM filter). If
the absolute pressure at this location is too low to extract an HC
sample, you may sample HC from the batch sampler pump's exhaust. Use
caution when sampling from pump exhaust because an otherwise acceptable
pump leak downstream of a batch sampler flow meter will cause a false
failure of the propane check.
(2) Repeat the propane check described in this section, but sample
HC from the batch sampler.
(3) Calculate C3H8 mass, taking into account any secondary dilution
from the batch sampler.
(4) Subtract the reference C3H8 mass from the calculated mass. If
this difference is within ±5% of the reference mass, the
batch sampler passes this verification. If not, take corrective action
as described in paragraph (a) of this section.

Sec. 1065.345 Vacuum-side leak verification.

(a) Scope and frequency. Upon initial sampling system installation,
after major maintenance, and before each test according to subpart F of
this part for laboratory tests and according to subpart J of this part
for field tests, verify that there are no significant vacuum-side leaks
using one of the leak tests described in this section.
(b) Measurement principles. A leak may be detected either by
measuring a small amount of flow when there should be zero flow, or by
detecting the dilution of a known concentration of span gas when it
flows through the vacuum side of a sampling system.
(c) Low-flow leak test. Test a sampling system for low-flow leaks
as follows:
(1) Seal the probe end of the system by taking one of the following
steps:
(i) Cap or plug the end of the sample probe.
(ii) Disconnect the transfer line at the probe and cap or plug the
transfer line.
(iii) Close a leak-tight valve in-line between a probe and transfer
line.
(2) Operate all vacuum pumps. After stabilizing, verify that the
flow through

[[Page 40554]]

the vacuum-side of the sampling system is less than 0.5 % of the
system's normal in-use flow rate. You may estimate typical analyzer and
bypass flows as an approximation of the system's normal in-use flow
rate.
(d) Dilution-of-span-gas leak test. Test any analyzer, other than a
FID, for dilution of span gas as follows, noting that this
configuration requires an overflow span gas system:
(1) Prepare a gas analyzer as you would for emission testing.
(2) Supply span gas to the analyzer port and verify that it
measures the span gas concentration within its expected measurement
accuracy and repeatability.
(3) Route overflow span gas to one of the following locations in
the sampling system:
(i) The end of the sample probe.
(ii) Disconnect the transfer line at the probe connection, and
overflow the span gas at the open end of the transfer line.
(iii) A three-way valve installed in-line between a probe and its
transfer line, such as a system overflow zero and span port.
(4) Verify that the measured overflow span gas concentration is
within the measurement accuracy and repeatability of the analyzer. A
measured value lower than expected indicates a leak, but a value higher
than expected may indicate a problem with the span gas or the analyzer
itself. A measured value higher than expected does not indicate a leak.

CO and CO2 Measurements

Sec. 1065.350 H2O interference verification for CO2 NDIR analyzers.

(a) Scope and frequency. If you measure CO2 using an NDIR analyzer,
verify the amount of H2O interference after initial analyzer
installation and after major maintenance.
(b) Measurement principles. H2O can interfere with an NDIR
analyzer's response to CO2.
If the NDIR analyzer uses compensation algorithms that utilize
measurements of other gases to meet this interference verification,
simultaneously conduct these other measurements to test the
compensation algorithms during the analyzer interference verification.
(c) System requirements. A CO2 NDIR analyzer must have an H2O
interference that is within ±2% of the flow-weighted mean
CO2 concentration expected at the standard, though we strongly
recommend a lower interference that is within ±1%.
(d) Procedure. Perform the interference verification as follows:
(1) Start, operate, zero, and span the CO2 NDIR analyzer as you
would before an emission test.
(2) Create a water-saturated test gas by bubbling zero air that
meets the specifications in Sec. 1065.750 through distilled water in a
sealed vessel at (25 ± 10) [deg]C.
(3) Introduce the water-saturated test gas upstream of any sample
dryer, if one is used during testing.
(4) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the transfer line and to
account for analyzer response.
(5) While the analyzer measures the sample's concentration, record
30 seconds of sampled data. Calculate the arithmetic mean of this data.
The analyzer meets the interference verification if this value is
within ±2% of the flow-weighted mean concentration of CO2
expected at the standard.
(e) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering
analysis that for your CO2 sampling system and your emission-
calculation procedures, the H2O interference for your CO2 NDIR analyzer
always affects your brake-specific emission results within < plus-
minus>0.5% of each of the applicable standards.
(2) You may use a CO₂ NDIR analyzer that you determine
does not meet this verification, as long as you try to correct the
problem and the measurement deficiency does not adversely affect your
ability to show that engines comply with all applicable emission standards.

Sec. 1065.355 H₂O and CO₂ interference
verification for CO NDIR analyzers.

(a) Scope and frequency. If you measure CO using an NDIR analyzer,
verify the amount of H₂O and CO₂ interference
after initial analyzer installation and after major maintenance.
(b) Measurement principles. H₂O and CO₂ can
positively interfere with an NDIR analyzer by causing a response
similar to CO. If the NDIR analyzer uses compensation algorithms that
utilize measurements of other gases to meet this interference
verification, simultaneously conduct these other measurements to test
the compensation algorithms during the analyzer interference
verification.
(c) System requirements. A CO NDIR analyzer must have combined
H₂O and CO₂ interference that is within 2 % of the flow-weighted mean concentration of CO expected at the
standard, though we strongly recommend a lower interference that is
within ±1%.
(d) Procedure. Perform the interference verification as follows:
(1) Start, operate, zero, and span the CO NDIR analyzer as you
would before an emission test.
(2) Create a water-saturated CO₂ test gas by bubbling a
CO₂ span gas through distilled water in a sealed vessel at
(25 ±10) [deg]C.
(3) Introduce the water-saturated CO₂ test gas upstream
of any sample dryer, if one is used during testing.
(4) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the transfer line and to
account for analyzer response.
(5) While the analyzer measures the sample's concentration, record
its output for 30 seconds. Calculate the arithmetic mean of this data.
(6) Multiply this mean value by the ratio of expected
CO₂ to span gas CO₂ concentration. In other
words, estimate the flow-weighted mean dry concentration of
CO₂ expected during testing, and then divide this value by
the concentration of CO₂ in the span gas used for this
verification. Then multiply this ratio by the mean value recorded
during this verification.
(7) The analyzer meets the interference verification if the result
of paragraph (d)(6) of this section is within ±2 % of the
flow-weighted mean concentration of CO expected at the standard.
(e) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering
analysis that for your CO sampling system and your emission
calculations procedures, the combined CO₂ and H₂O
interference for your CO NDIR analyzer always affects your brake-
specific CO emission results within ±0.5 % of the applicable
CO standard.(2) You may use a CO NDIR analyzer that you determine does
not meet this verification, as long as you try to correct the problem
and the measurement deficiency does not adversely affect your ability
to show that engines comply with all applicable emission standards.

Hydrocarbon Measurements

Sec. 1065.360 FID optimization and verification.

(a) Scope and frequency. For all FID analyzers perform the
following steps:
(1) Calibrate a FID upon initial installation. Repeat the
calibration as needed using good engineering judgment.
(2) Optimize a FID's response to various hydrocarbons after initial

[[Page 40555]]

analyzer installation and after major maintenance.
(3) Determine a FID's methane (CH₄) response factor
after initial analyzer installation and after major maintenance.
(4) Verify methane (CH₄) response within 185 days before
testing.
(b) Calibration. Use good engineering judgment to develop a
calibration procedure, such as one based on the FID-analyzer
manufacturer's instructions and recommended frequency for calibrating
the FID. Alternately, you may remove system components for off-site
calibration. Calibrate using C₃H₈ calibration
gases that meet the specifications of Sec. 1065.750. We recommend FID
analyzer zero and span gases that contain approximately the flow-
weighted mean concentration of O₂ expected during testing.
If you use a FID to measure methane (CH₄) downstream of a
nonmethane cutter, you may calibrate that FID using CH₄
calibration gases with the cutter. Regardless of the calibration gas
composition, calibrate on a carbon number basis of one (C₁).
For example, if you use a C₃H₈ span gas of
concentration 200 [mu]mol/mol, span the FID to respond with a value of
600 [mu]mol/mol.
(c) FID response optimization. Use good engineering judgment for
initial instrument start-up and basic operating adjustment using FID
fuel and zero air. Heated FIDs must be within their required operating
temperature ranges. Optimize FID response at the most common analyzer
range expected during emission testing. Optimization involves adjusting
flows and pressures of FID fuel, burner air, and sample to minimize
response variations to various hydrocarbon species in the exhaust. Use
good engineering judgment to trade off peak FID response to propane
calibration gases to achieve minimal response variations to different
hydrocarbon species. For an example of trading off response to propane
for relative responses to other hydrocarbon species, see SAE 770141
(incorporated by reference in Sec. 1065.1010). Determine the optimum
flow rates for FID fuel, burner air, and sample and record them for
future reference.
(d) CH4 response factor determination. Since FID analyzers
generally have a different response to CH₄ versus C3H8,
determine each FID analyzer's CH₄ response factor,
RF_CH4, after FID optimization. Use the most recent
RF_CH4 measured according to this section in the calculations
for HC determination described in Sec. 1065.660 to compensate for
CH₄ response. Determine RF_CH4 as follows, noting
that you do not determine RF_CH4 for FIDs that are calibrated
and spanned using CH₄ with a nonmethane cutter:
(1) Select a C₃H₈ span gas that meets the
specifications of Sec. 1065.750. Record the C₃H₈
concentration of the gas.
(2) Select a CH₄ span gas that meets the specifications
of Sec. 1065.750. Record the CH₄ concentration of the gas.
(3) Start and operate the FID analyzer according to the
manufacturer's instructions.
(4) Confirm that the FID analyzer has been calibrated using
C₃H₈. Calibrate on a carbon number basis of one
(C₁). For example, if you use a C₃H₈
span gas of concentration 200 [mu]mol/mol, span the FID to respond with
a value of 600 [mu]mol/mol.
(5) Zero the FID with a zero gas that you use for emission testing.
(6) Span the FID with the C₃H₈ span gas that
you selected under paragraph (d)(1) of this section.
(7) Introduce at the sample port of the FID analyzer, the
CH₄ span gas that you selected under paragraph (d)(2) of
this section.
(8) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the analyzer and to
account for its response.
(9) While the analyzer measures the CH₄ concentration,
record 30 seconds of sampled data. Calculate the arithmetic mean of
these values.
(10) Divide the mean measured concentration by the recorded span
concentration of the CH₄ calibration gas. The result is the
FID analyzer's response factor for CH₄, RF_CH4.
(e) FID methane (CH₄) response verification. If the
value of RF_CH4 from paragraph (d) of this section is within
±5.0% of its most recent previously determined value, the
FID passes the methane response verification. For example, if the most
recent previous value for RF_CH4 was 1.05 and it changed by
+0.05 to become 1.10 or it changed by -0.05 to become 1.00, either case
would be acceptable because +4.8% is less than +5.0%.
(1) Verify that the pressures and flow rates of FID fuel, burner
air, and sample are each within ±0.5% of their most recent
previously recorded values, as described in paragraph (c) of this
section. You may adjust these flow rates as necessary. Determine a new
RF_CH4 as described in paragraph (d) of this section.
(2) If RF_CH4 is still not within ±5.0% of its
most recently determined value after adjusting flow rates, re-optimize
the FID response as described in paragraph (c) of this section.
(3) Determine a new RF_CH4 as described in paragraph (d)
of this section. Use this new value of RF_CH4 in the
calculations for HC determination, as described in Sec. 1065.660.

Sec. 1065.362 Non-stoichiometric raw exhaust FID O₂
interference verification.

(a) Scope and frequency. If you use FID analyzers for raw exhaust
measurements from engines that operate in a non-stoichiometric mode of
combustion (e.g., compression-ignition, lean-burn), verify the amount
of FID O₂ interference upon initial installation and after
major maintenance.
(b) Measurement principles. Changes in O₂ concentration
in raw exhaust can affect FID response by changing FID flame
temperature. Optimize FID fuel, burner air, and sample flow to meet
this verification. Verify FID performance with the compensation
algorithms for FID O₂ interference that you have active
during an emission test.
(c) System requirements. Any FID analyzer used during testing must
meet the FID O₂ interference verification according to the
procedure in this section.
(d) Procedure. Determine FID O₂ interference as follows:
(1) Select two span reference gases that meet the specifications in
Sec. 1065.750 and contain C₃H₈ near 100% of span
for HC. You may use CH₄ span reference gases for FIDs
calibrated on CH₄ with a nonmethane cutter. Select the two
balance gas concentrations such that the concentrations of
O₂ and N₂ represent the minimum and maximum
O₂ concentrations expected during testing.
(2) Confirm that the FID analyzer meets all the specifications of
Sec. 1065.360.
(3) Start and operate the FID analyzer as you would before an
emission test. Regardless of the FID burner's air source during
testing, use zero air as the FID burner's air source for this verification.
(4) Zero the FID analyzer using the zero gas used during emission
testing.
(5) Span the FID analyzer using the span gas used during emission
testing.
(6) Check the zero response of the FID analyzer using the zero gas
used during emission testing. If the mean zero response of 30 seconds
of sampled data is within ±0.5% of the span reference value
used in paragraph (d)(5) of this section, then proceed to the next
step; otherwise restart the procedure at paragraph (d)(4) of this
section.
(7) Check the analyzer response using the span gas that has the
minimum concentration of O₂ expected during testing. Record
the mean response of 30 seconds of stabilized sample data as
x_O2minHC.
(8) Check the zero response of the FID analyzer using the zero gas
used during

[[Page 40556]]

emission testing. If the mean zero response of 30 seconds of stabilized
sample data is within ±0.5% of the span reference value used
in paragraph (d)(5) of this section, then proceed to the next step;
otherwise restart the procedure at paragraph (d)(4) of this section.
(9) Check the analyzer response using the span gas that has the
maximum concentration of O₂ expected during testing. Record
the mean response of 30 seconds of stabilized sample data as
x_O2maxHC.
(10) Check the zero response of the FID analyzer using the zero gas
used during emission testing. If the mean zero response of 30 seconds
of stabilized sample data is within ±0.5% of the span
reference value used in paragraph (d)(5) of this section, then proceed
to the next step; otherwise restart the procedure at paragraph (d)(4)
of this section.
(11) Calculate the percent difference between x_O2maxHC
and its reference gas concentration. Calculate the percent difference
between x_O2minHC and its reference gas concentration.
Determine the maximum percent difference of the two. This is the
O₂ interference.
(12) If the O₂ interference is within ±1.5%,
then the FID passes the O₂ interference check; otherwise
perform one or more of the following to address the deficiency:
(i) Select zero and span gases for emission testing that contain
higher or lower O₂ concentrations.
(ii) Adjust FID burner air, fuel, and sample flow rates. Note that
if you adjust these flow rates to meet the O₂ interference
verification, you must re-verify with the adjusted flow rates that the
FID meets the CH₄ response factor verification according to
Sec. 1065.360.
(iii) Repair or replace the FID.
(iv) Demonstrate that the deficiency does not adversely affect your
ability to demonstrate compliance with the applicable emission standards.

Sec. 1065.365 Nonmethane cutter penetration fractions.

(a) Scope and frequency. If you use a FID analyzer and a nonmethane
cutter (NMC) to measure methane (CH₄), determine the
nonmethane cutter's penetration fractions of methane, PF_CH4,
and ethane, PF_C2H6. Perform this verification after
installing the nonmethane cutter. Repeat this verification within 185
days of testing to verify that the catalytic activity of the cutter has
not deteriorated. Note that because nonmethane cutters can deteriorate
rapidly and without warning if they are operated outside of certain
ranges of gas concentrations and outside of certain temperature ranges,
good engineering judgment may dictate that you determine a nonmethane
cutter's penetration fractions more frequently.
(b) Measurement principles. A nonmethane cutter is a heated
catalyst that removes nonmethane hydrocarbons from the exhaust stream
before the FID analyzer measures the remaining hydrocarbon
concentration. An ideal nonmethane cutter would have PF_CH4
of 1.000, and the penetration fraction for all other hydrocarbons would
be 0.000, as represented by PF_C2H6. The emission
calculations in Sec. 1065.660 use this section's measured values of
PF_CH4 and PF_C2H6 to account for less than ideal
NMC performance.
(c) System requirements. We do not limit NMC penetration fractions
to a certain range. However, we recommend that you optimize a
nonmethane cutter by adjusting its temperature to achieve
PF_CH4 >0.95 and PF_C2H6 <0.02 as determined by
paragraphs (d) and (e) of this section, as applicable. If we use a
nonmethane cutter for testing, it will meet this recommendation. If
adjusting NMC temperature does not result in achieving both of these
specifications simultaneously, we recommend that you replace the
catalyst material.
Use the most recently determined penetration values from this
section to calculate HC emissions according to Sec. 1065.660 and Sec.
1065.665 as applicable.
(d) Procedure for a FID calibrated with the NMC. If your FID
arrangement is such that a FID is always calibrated to measure
CH₄ with the NMC, then span that FID with the NMC cutter
using a CH₄ span gas, set that FID's CH₄
penetration fraction, PF_CH4, equal to 1.0 for all emission
calculations, and determine its ethane (C₂H₆)
penetration fraction, PF_C2H6. as follows:
(1) Select a CH₄ gas mixture and a
C₂H₆ analytical gas mixture and ensure that both
mixtures meet the specifications of Sec. 1065.750. Select a
CH₄ concentration that you would use for spanning the FID
during emission testing and select a C₂H₆
concentration that is typical of the peak NMHC concentration expected
at the hydrocarbon standard or equal to THC analyzer's span value.
(2) Start, operate, and optimize the nonmethane cutter according to
the manufacturer's instructions, including any temperature optimization.
(3) Confirm that the FID analyzer meets all the specifications of
Sec. 1065.360.
(4) Start and operate the FID analyzer according to the
manufacturer's instructions.
(5) Zero and span the FID with the cutter and use CH₄
span gas to span the FID with the cutter. Note that you must span the
FID on a C₁ basis. For example, if your span gas has a
CH₄ reference value of 100 [mu]/mol, the correct FID
response to that span gas is 100 [mu]/mol because there is one carbon
atom per CH₄ molecule.
(6) Introduce the C₂H₆ analytical gas mixture
upstream of the nonmethane cutter.
(7) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the nonmethane cutter and
to account for the analyzer's response.
(8) While the analyzer measures a stable concentration, record 30
seconds of sampled data. Calculate the arithmetic mean of these data
points.
(9) Divide the mean by the reference value of
C₂H₆, converted to a C₁ basis. The
result is the C₂H₆ penetration fraction,
PF_C2H6. Use this penetration fraction and the CH₄
penetration fraction, which is set equal to 1.0, in emission
calculations according to Sec. 1065.660 or Sec. 1065.665, as applicable.
(e) Procedure for a FID calibrated by bypassing the NMC. If you use
a FID with an NMC that is calibrated by bypassing the NMC, determine
penetration fractions as follows:
(1) Select CH₄ and C₂H₆ analytical
gas mixtures that meet the specifications of Sec. 1065.750 with the
CH₄ concentration typical of its peak concentration expected
at the hydrocarbon standard and the C₂H₆
concentration typical of the peak total hydrocarbon (THC) concentration
expected at the hydrocarbon standard or the THC analyzer span value.
(2) Start and operate the nonmethane cutter according to the
manufacturer's instructions, including any temperature optimization.
(3) Confirm that the FID analyzer meets all the specifications of
Sec. 1065.360.
(4) Start and operate the FID analyzer according to the
manufacturer's instructions.
(5) Zero and span the FID as you would during emission testing.
Span the FID by bypassing the cutter and by using
C₃H₈ span gas to span the FID. Note that you must
span the FID on a C₁ basis. For example, if your span gas
has a propane reference value of 100 [mu]/mol, the correct FID response
to that span gas is 300 [mu]/mol because there are three carbon atoms
per C₃H₈ molecule.
(6) Introduce the C₂H₆ analytical gas mixture
upstream of the nonmethane cutter.
(7) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the nonmethane cutter and
to account for the analyzer's response.

[[Page 40557]]

(8) While the analyzer measures a stable concentration, record 30
seconds of sampled data. Calculate the arithmetic mean of these data points.
(9) Reroute the flow path to bypass the nonmethane cutter,
introduce the C₂H₆ analytical gas mixture to the
bypass, and repeat the steps in paragraphs (e)(7) through (8) of this
section.
(10) Divide the mean C₂H₆ concentration
measured through the nonmethane cutter by the mean concentration
measured after bypassing the nonmethane cutter. The result is the
C₂H₆ penetration fraction, PF_C2H6. Use
this penetration fraction according to Sec. 1065.660 or Sec.
1065.665, as applicable.
(11) Repeat the steps in paragraphs (e)(6) through (10) of this
section, but with the CH₄ analytical gas mixture instead of
C₂H₆. The result will be the CH₄
penetration fraction, PF_CH4. Use this penetration fraction
according to Sec. 1065.660 or Sec. 1065.665, as applicable.

No_X Measurements

Sec. 1065.370 CLD CO2 and H2O quench verification.

(a) Scope and frequency. If you use a CLD analyzer to measure
NO_X, verify the amount of H₂O and CO₂
quench after installing the CLD analyzer and after major maintenance.
(b) Measurement principles. H₂O and CO₂ can
negatively interfere with a CLD's NO_X response by
collisional quenching, which inhibits the chemiluminescent reaction
that a CLD utilizes to detect NO_X. The calculations in Sec.
1065.672 for H₂O quench account for the water vapor in
humidified NO span gas. The procedure and the calculations scale the
quench results to the water vapor and CO₂ concentrations
expected during testing. If the CLD analyzer uses quench compensation
algorithms that utilize H₂O and/or CO₂
measurement instruments, use these instruments to measure
H₂O and/or CO₂ and evaluate quench with the
compensation algorithms applied.
(c) System requirements. A CLD analyzer must have a combined
H₂O and CO₂ quench of ±2% or less,
though we strongly recommend a quench of ±1% or less.
Combined quench is the sum of the CO₂ quench determined as
described in paragraph (d) of this section, plus the H₂O
quench determined in paragraph (e) of this section.
(d) CO2 quench verification procedure. Use the following method to
determine CO₂ quench, or use good engineering judgment to
develop a different protocol:
(1) Use PTFE tubing to make necessary connections.
(2) Connect a pressure-regulated CO₂ span gas to one of
the inlets of a three-way valve made of 300 series stainless steel. Use
a CO₂ span gas that meets the specifications of Sec.
1065.750 and attempt to use a concentration that is approximately twice
the maximum CO₂ concentration expected to enter the CLD
sample port during testing, if available.
(3) Connect a pressure-regulated purified N₂ gas to the
valve's other inlet. Use a purified N₂ gas that meets the
specifications of Sec. 1065.750.
(4) Connect the valve's single outlet to the balance-gas port of a
gas divider that meets the specifications in Sec. 1065.248.
(5) Connect a pressure-regulated NO span gas to the span-port of
the gas divider. Use an NO span gas that meets the specifications of
Sec. 1065.750. Attempt to use an NO concentration that is
approximately twice the maximum NO concentration expected during
testing, if available.
(6) Configure the gas divider such that nearly equal amounts of the
span gas and balance gas are blended with each other. Apply viscosity
corrections as necessary to appropriately ensure correct gas division.
(7) While flowing balance and span gases through the gas divider,
stabilize the CO₂ concentration downstream of the gas
divider and measure the CO₂ concentration with an NDIR
analyzer that has been prepared for emission testing. Record this
concentration, X_CO2meas, and use it in the quench
verification calculations in Sec. 1065.675.
(8) Measure the NO concentration downstream of the gas divider. If
the CLD has an operating mode in which it detects NO-only, as opposed
to total NO_X, operate the CLD in the NO-only operating mode.
Record this concentration, X_NO,CO2, and use it in the quench
verification calculations in Sec. 1065.675.
(9) Switch the three-way valve so 100% purified N₂ flows
to the gas divider's balance-port inlet. Monitor the CO₂ at
the gas divider's outlet until its concentration stabilizes at zero.
(10) Measure NO concentration at the gas divider's outlet. Record
this value, X_NO,N2 , and use it in the quench verification
calculations in Sec. 1065.675.
(11) Use the values recorded according to this paragraph (d) of
this section and paragraph (e) of this section to calculate quench as
described in Sec. 1065.675.
(e) H₂O quench verification procedure. Use the following
method to determine H₂O quench, or use good engineering
judgment to develop a different protocol:
(1) Use PTFE tubing to make necessary connections.
(2) If the CLD has an operating mode in which it detects NO-only,
as opposed to total NO_X, operate the CLD in the NO-only
operating mode.
(3) Measure an NO calibration span gas that meets the
specifications of Sec. 1065.750 and is near the maximum concentration
expected during testing. Record this concentration, X_NOdry.
(4) Humidify the gas by bubbling it through distilled water in a
sealed vessel. We recommend that you humidify the gas to the highest
sample dewpoint that you estimate during emission sampling. Regardless
of the humidity during this test, the quench verification calculations
in Sec. 1065.675 scale the recorded quench to the highest dewpoint
that you expect entering the CLD sample port during emission sampling.
(5) If you do not use any sample dryer for NO_X during
emissions testing, record the vessel water temperature as
T_dew, and its pressure as p_total and use these
values according to Sec. 1065.645 to calculate the amount of water
entering the CLD sample port, X_H2Omeas. If you do use a
sample dryer for NO_X during emissions testing, measure the
humidity of the sample just upstream of the CLD sample port and use the
measured humidity according to Sec. 1065.645 to calculate the amount
of water entering the CLD sample port, X_H2Omeas.
(6) To prevent subsequent condensation, make sure that any
humidified sample will not be exposed to temperatures lower than
T_dew during transport from the sealed vessel's outlet to the
CLD. We recommend using heated transfer lines.
(7) Introduce the humidified sample upstream of any sample dryer,
if one is used.
(8) Use the CLD to measure the NO concentration of the humidified
span gas and record this value, X_NOwet.
(9) Use the recorded values from this paragraph (e) to calculate
the quench as described in Sec. 1065.675.
(10) Use the values recorded according to this paragraph (e) of
this section and paragraph (d) of this section to calculate quench as
described in Sec. 1065.675.
(f) Corrective action. If the sum of the H₂O quench plus
the CO₂ quench is not within ±2%, take corrective
action by repairing or replacing the analyzer. Before using a CLD for
emission testing, demonstrate that the corrective action resulted in a
value within ±2% combined quench.
(g) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering
analysis that for your NO_X sampling system and

[[Page 40558]]

your emission calculations procedures, the the combined CO₂
and H₂O interference for your NO_X CLD analyzer
always affects your brake-specific NO_X emission results
within no more than ±1.0% of the applicable NO_X
standard.
(2) You may use a NO_X CLD analyzer that you determine
does not meet this verification, as long as you try to correct the
problem and the measurement deficiency does not adversely affect your
ability to show that engines comply with all applicable emission
standards.

Sec. 1065.372 NDUV analyzer HC and H₂O interference
verification.

(a) Scope and frequency. If you measure NO_X using an
NDUV analyzer, verify the amount of H₂O and hydrocarbon
interference after initial analyzer installation and after major
maintenance.
(b) Measurement principles. Hydrocarbons and H₂O can
positively interfere with an NDUV analyzer by causing a response
similar to NO_X. If the NDUV analyzer uses compensation
algorithms that utilize measurements of other gases to meet this
interference verification, simultaneously conduct such measurements to
test the algorithms during the analyzer interference verification.
(c) System requirements. A NO_X NDUV analyzer must have
combined H2O and HC interference within ±2% of the flow-
weighted mean concentration of NO_X expected at the standard,
though we strongly recommend keeping interference within < plus-minus>1%.
(d) Procedure. Perform the interference verification as follows:
(1) Start, operate, zero, and span the NO_X NDUV analyzer
according to the instrument manufacturer's instructions.
(2) We recommend that you extract engine exhaust to perform this
verification. Use a CLD that meets the specifications of subpart C of
this part to quantify NO_X in the exhaust. Use the CLD
response as the reference value. Also measure HC in the exhaust with a
FID analyzer that meets the specifications of subpart C of this part.
Use the FID response as the reference hydrocarbon value.
(3) Upstream of any sample dryer, if one is used during testing,
introduce the engine exhaust to the NDUV analyzer.
(4) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the transfer line and to
account for analyzer response.
(5) While all analyzers measure the sample's concentration, record
30 seconds of sampled data, and calculate the arithmetic means for the
three analyzers.
(6) Subtract the CLD mean from the NDUV mean.
(7) Multiply this difference by the ratio of the flow-weighted mean
HC concentration expected at the standard to the HC concentration
measured during the verification. The analyzer meets the interference
verification of this section if this result is within ±2% of
the HC concentration expected at the standard.
(e) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering
analysis that for your NO_X sampling system and your emission
calculations procedures, the the combined HC and H₂O
interference for your NO_X NDUV analyzer always affects your
brake-specific NO_X emission results by less than 0.5% of the
applicable NO_X standard.
(2) You may use a NO_X NDUV analyzer that you determine
does not meet this verification, as long as you try to correct the
problem and the measurement deficiency does not adversely affect your
ability to show that engines comply with all applicable emission
standards.

Sec. 1065.376 Chiller NO2 penetration.

(a) Scope and frequency. If you use a chiller to dry a sample
upstream of a NO_X measurement instrument, but you don't use
an NO₂-to-NO converter upstream of the chiller, you must
perform this verification for chller NO₂ penetration.
Perform this verification after initial installation and after major
maintenance.
(b) Measurement principles. A chiller removes water, which can
otherwise interfere with a NO_X measurement. However, liquid
water in an improperly designed chiller can remove NO₂ from
the sample. If a chiller is used without an NO₂-to-NO
converter upstream, it could therefore remove NO₂ from the
sample prior NO_X measurement.
(c) System requirements. A chiller must allow for measuring at
least 95% of the total NO₂ at the maximum expected
concentration of NO₂.
(d) Procedure. Use the following procedure to verify chiller
performance:
(1) Instrument setup. Follow the analyzer and chiller
manufacturers' start-up and operating instructions. Adjust the analyzer
and chiller as needed to optimize performance.
(2) Equipment setup. Connect an ozonator's inlet to a zero-air or
oxygen source and connect its outlet to one port of a three-way tee
fitting. Connect an NO span gas to another port of the tee. Connect a
heated line at 100 [deg]C to the last port, and connect a heated three-
way tee to the other end of the line. Connect a dewpoint generator, set
at a dewpoint of 50 [deg]C, to one end of a heated line at 100 [deg]C.
Connect the other end of the line to the heated tee and connect a third
100 [deg]C heated line to the chiller inlet. Provide an overflow vent
line at the chiller inlet.
(3) Adjustments. For the following adjustment steps, set the
analyzer to measure only NO (i.e., NO mode), or only read the NO
channel of the analyzer:
(i) With the dewpoint generator and the ozonator off, adjust the NO
and zero-gas flows so the NO concentration at the analyzer is at least
two times the peak total NO_X concentration expected during
testing at the standard. Verify that gas is flowing out of the overflow
vent line.
(ii) Turn on the dewpoint generator and adjust its flow so the NO
concentration at the analyzer is at least at the peak total
NO_X concentration expected during testing at the standard.
Verify that gas is flowing out of the overflow vent line.
(iii) Turn on the ozonator and adjust the ozonator so the NO
concentration measured by the analyzer decreases by the same amount as
the maximum concentration of NO₂ expected during testing.
This ensures that the ozonator is generating NO₂ at the
maximum concentration expected during testing.
(4) Data collection. Maintain the ozonator adjustment in paragraph
(d)(3) of this section, and keep the NO_X analyzer in the NO
only mode or only read the NO channel of the analyzer.
(i) Allow for stabilization, accounting only for transport delays
and instrument response.
(ii) Calculate the mean of 30 seconds of sampled data from the
analyzer and record this value as NO_ref.
(iii) Switch the analyzer to the total NO_X mode, (that
is, sum the NO and NO₂ channels of the analyzer) and allow
for stabilization, accounting only for transport delays and instrument
response.
(iv) Calculate the mean of 30 seconds of sampled data from the
analyzer and record this value as NOx_meas.
(v) Turn off the ozonator and allow for stabilization, accounting
only for transport delays and instrument response.
(vi) Calculate the mean of 30 seconds of sampled data from the
analyzer and record this value as NO_xref.
(5) Performance evaluation. Divide the quantity of
(NO_xmeas-NO_ref) by the quantity of
(NO_xref-NO_ref). If the result

[[Page 40559]]

is less than 95%, repair or replace the chiller.
(e) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering
analysis that for your NO_X sampling system and your emission
calculations procedures, the the chiller always affects your brake-
specific NO_X emission results by less than 0.5% of the
applicable NO_X standard.
(2) You may use a chiller that you determine does not meet this
verification, as long as you try to correct the problem and the
measurement deficiency does not adversely affect your ability to show
that engines comply with all applicable emission standards.

Sec. 1065.378 NO₂-to-NO converter conversion verification.

(a) Scope and frequency. If you use an analyzer that measures only
NO to determine NO_X, you must use an NO2-to-NO converter
upstream of the analyzer. Perform this verification after installing
the converter, after major maintenance and within 35 days before an
emission test. This verification must be repeated at this frequency to
verify that the catalytic activity of the NO₂-to-NO
converter has not deteriorated.
(b) Measurement principles. An NO2-to-NO converter allows an
analyzer that measures only NO to determine total NO_X by
converting the NO2 in exhaust to NO.
(c) System requirements. An NO2-to-NO converter must allow for
measuring at least 95% of the total NO2 at the maximum expected
concentration of NO2.
(d) Procedure. Use the following procedure to verify the
performance of a NO2-to-NO converter:
(1) Instrument setup. Follow the analyzer and NO2-to-NO converter
manufacturers' start-up and operating instructions. Adjust the analyzer
and converter as needed to optimize performance.
(2) Equipment setup. Connect an ozonator's inlet to a zero-air or
oxygen source and connect its outlet to one port of a 4-way cross
fitting. Connect an NO span gas to another port. Connect the NO2-to-NO
converter inlet to another port, and connect an overflow vent line to
the last port.
(3) Adjustments. Take the following steps to make adjustments:
(i) With the NO2-to-NO converter in the bypass mode (i.e., NO mode)
and the ozonator off, adjust the NO and zero-gas flows so the NO
concentration at the analyzer is at the peak total NO_X
concentration expected during testing. Verify that gas is flowing out
of the overflow vent.
(ii) With the NO2-to-NO converter still in the bypass mode, turn on
the ozonator and adjust the ozonator so the NO concentration measured
by the analyzer decreases by the same amount as maximum concentration
of NO2 expected during testing. This ensures that the ozonator is
generating NO2 at the maximum concentration expected during testing.
(4) Data collection. Maintain the ozonator adjustment in paragraph
(d)(3) of this section, and keep the NO_X analyzer in the NO
only mode (i.e., bypass the NO2-to-NO converter).
(i) Allow for stabilization, accounting only for transport delays
and instrument response.
(ii) Calculate the mean of 30 seconds of sampled data from the
analyzer and record this value as NO_ref.
(iii) Switch the analyzer to the total NO_X mode (that
is, sample with the NO2-to-NO converter) and allow for stabilization,
accounting only for transport delays and instrument response.
(iv) Calculate the mean of 30 seconds of sampled data from the
analyzer and record this value as NO_xmeas.
(v) Turn off the ozonator and allow for stabilization, accounting
only for transport delays and instrument response.
(vi) Calculate the mean of 30 seconds of sampled data from the
analyzer and record this value as NO_xref.
(5) Performance evaluation. Divide the quantityof
(NO_xmeas -NO_ref)by the quantity of
(NO_xref -NO_ref). If the result is less than 95%,
repair or replace the NO2-to-NO converter.
(e) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering
analysis that for your NO_x sampling system and your emission
calculations procedures, the converter always affects your brake-
specific NO_x emission results by less than 0.5% of the
applicable NO_x standard.
(2) You may use a converter that you determine does not meet this
verification, as long as you try to correct the problem and the
measurement deficiency does not adversely affect your ability to show
that engines comply with all applicable emission standards.

PM Measurements

Sec. 1065.390 PM balance verifications and weighing process
verification.

(a) Scope and frequency. This section describes three
verifications. The first verification requires an independent
verification of PM balance performance, and this must be performed
within 370 days before emission testing. The second verification
requires zeroing and spanning the balance, and this must be performed
within 12 h before weighing. The third verification requires comparing
a current mass determination of pooled reference samples with the
previous mass determination of the pooled reference samples. This
verification must be performed within 12 h before weighing.
(b) Independent verification. Have the balance manufacturer (or a
representative approved by the balance manufacturer) verify the balance
performance within 370 days of testing.
(c) Zeroing and spanning. You must verify balance performance by
zeroing and spanning it with at least one calibration weight, and any
weights you use must that meet the specifications in Sec. 1065.790 to
perform this verification.
(1) Use a manual procedure in which you zero the balance and span
the balance with at least one calibration weight. If you normally use
mean values by repeating the weighing process to improve the accuracy
and precision of PM measurements, use the same process to verify
balance performance.
(2) You may use an automated procedure to verify balance
performance. For example many balances have internal calibration
weights that are used automatically to verify balance performance. Note
that if you use internal balance weights, the weights must meet the
specifications in Sec. 1065.790 to perform this verification.
(d) Reference sample weighing. You must also verify the PM-weighing
environment and weighing process by weighing reference PM sample media.
Repeated weighing of a reference mass must return the same value within
±10 [mu]g or ±10% of the net PM mass expected at
the standard (if known), whichever is higher. Perform this verification
as follows:
(1) Keep at least two samples of unused PM sample media in the PM-
stabilization environment. Use these as references. If you collect PM
with filters, select unused filters of the same material and size for
use as references. You may periodically replace references, using good
engineering judgment.
(2) Stabilize references in the PM stabilization environment.
Consider references stabilized if they have been in the PM-
stabilization environment for a minimum of 30 min, and the PM-
stabilization environment has been within the specifications of

[[Page 40560]]

Sec. 1065.190(d) for at least the preceding 60 min.
(3) Exercise the balance several times with a reference sample. We
recommend weighing ten samples without recording the values.
(4) Zero and span the balance.
(5) Weigh each of the reference samples and record their masses. We
recommend using substitution weighing as described in Sec.
1065.590(j). If you normally use mean values by repeating the weighing
process to improve the accuracy and precision of PM measurements, use
the same process to measure reference masses.
(6) Record the balance environment dewpoint, ambient temperature,
and atmospheric pressure.
(7) Use the recorded ambient conditions to correct results for
buoyancy as described in Sec. 1065.690. Record the buoyancy-corrected
mass of each of the references.
(8) Subtract each of the reference's buoyancy-corrected masses from
the most recent previous determinations of their masses.
(9) If the mean of the reference's masses changes by more than that
allowed under paragraph (d) of this section, then invalidate all PM
results that were determined between the two times that the reference
masses were determined.

Sec. 1065.395 Inertial PM balance verifications.

This section describes how to verify the performance of an inertial
PM balance.
(a) Independent verification. Have the balance manufacturer (or a
representative approved by the balance manufacturer) verify the
inertial balance performance within 370 days before testing.
(b) Other verifications. Perform other verifications using good
engineering judgment and instrument manufacturer recommendations.

Subpart E--Engine Selection, Preparation, and Maintenance

Sec. 1065.401 Test engine selection.

While all engine configurations within a certified engine family
must comply with the applicable standards in the standard-setting part,
you need not test each configuration for certification.
(a) Select an engine configuration within the engine family for
testing, as follows:
(1) Test the engine that we specify, whether we issue general
guidance or give you specific instructions.
(2) If we do not tell you which engine to test, follow any
instructions in the standard-setting part.
(3) If we do not tell you which engine to test and the standard-
setting part does not include specifications for selecting test
engines, use good engineering judgment to select the engine
configuration within the engine family that is most likely to exceed an
emission standard.
(b) In the absence of other information, the following
characteristics are appropriate to consider when selecting the engine
to test:
(1) Maximum fueling rates.
(2) Maximum loads.
(3) Maximum in-use speeds.
(4) Highest sales volume.
(c) For our testing, we may select any engine configuration within
the engine family.

Sec. 1065.405 Test engine preparation and maintenance.

(a) If you are testing an emission-data engine for certification,
make sure it is built to represent production engines. This includes
governors that you normally install on production engines. If you do
not install governors on production engines, simulate a governor that
is representative of a governor that others will install on your
production engines.
(b) Run the test engine, with all emission-control systems
operating, long enough to stabilize emission levels. Unless otherwise
specified in the standard-setting part, you may consider emission
levels stable without measurement if you accumulate 12 h of operation
for a spark-ignition engine or 125 h for a compression-ignition engine.
If the engine needs more or less operation to stabilize emission
levels, record your reasons and the methods for doing this, and give us
these records if we ask for them. To ensure consistency between low-
hour engines and deterioration factors, you must use the same
stabilization procedures for all emission-data engines within an engine
family.
(c) Record any maintenance, modifications, parts changes,
diagnostic or emissions testing and document the need for each event.
You must provide this information if we request it.
(d) For accumulating operating hours on your test engines, select
engine operation that represents normal in-use operation for the engine
family.
(e) If your engine will be used in a vehicle equipped with a
canister for storing evaporative hydrocarbons for eventual combustion
in the engine, attach a canister to the engine before running an
emission test. You may request to omit using an evaporative canister
during testing if you can show that it would not affect your ability to
show compliance with the applicable emission standards. You do not have
to accumulate engine operation before emission testing with an
installed canister. Prior to an emission test, use the following steps
to attach a canister to your engine:
(1) Use a canister and plumbing arrangement that represents the in-
use configuration of the largest capacity canister in all expected
applications.
(2) Use a canister that is fully loaded with fuel vapors.
(3) Connect the canister's purge port to the engine.
(4) Plug the canister port that is normally connected to the fuel tank.

Sec. 1065.410 Maintenance limits for stabilized test engines.

(a) After you stabilize the test engine's emission levels, you may
do maintenance as allowed by the standard-setting part. However, you
may not do any maintenance based on emission measurements from the test
engine (i.e., unscheduled maintenance).
(b) For any critical emission-related maintenance--other than what
we specifically allow in the standard-setting part--you must completely
test an engine for emissions before and after doing any maintenance
that might affect emissions, unless we waive this requirement.
(c) Keep a record of the inspection and update your application to
document any changes as a result of the inspection. You may use
equipment, instruments, or tools to identify bad engine components. Any
equipment, instruments, or tools used for scheduled maintenance on
emission data engines must be available to dealerships and other
service outlets.
(d) You may adjust or repair an emission-data engine as long as you
document these changes in your application.
(e) If we determine that a part failure, system malfunction, or
associated repairs have made the engine's emission controls
unrepresentative of production engines, you may no longer use it as an
emission-data. Also, if your test engine has a major mechanical failure
that requires you to take it apart, you may no longer use it as an
emission-data engine.

Sec. 1065.415 Durability demonstration.

If the standard-setting part requires durability testing, you must
accumulate service in a way that represents how you expect the engine
to operate in use. You may accumulate service hours using an
accelerated schedule, such as through continuous operation or by using
duty cycles that are more aggressive than in-use operation.

[[Page 40561]]

(a) Maintenance. The following limits apply to the maintenance that
we allow you to do on an emission-data engine:
(1) You may perform scheduled maintenance that you recommend to
operators, but only if it is consistent with the standard-setting
part's restrictions.
(2) You may perform additional maintenance only as specified in
Sec. 1065.410 or allowed by the standard-setting part.
(3) We may approve additional maintenance to your durability engine
if all the following occur:
(i) Something clearly malfunctions--such as persistent misfire,
engine stall, overheating, fluid leaks, or loss of oil pressure--and
needs maintenance or repair.
(ii) You provide us an opportunity to verify the extent of the
malfunction before you do the maintenance.
(b) Emission measurements. Perform emission tests following the
provisions of the standard setting part and this part, as applicable.
Perform emission tests to determine deterioration factors consistent
with good engineering judgment. Evenly space any tests between the
first and last test points throughout the durability period, unless we
approve otherwise.

Subpart F--Performing an Emission Test in the Laboratory

Sec. 1065.501 Overview.

(a) Use the procedures detailed in this subpart to measure engine
emissions in a laboratory setting. This section describes how to:
(1) Map your engine by recording specified speed and torque data,
as measured from the engine's primary output shaft.
(2) Transform normalized duty cycles into reference duty cycles for
your engine by using an engine map.
(3) Prepare your engine, equipment, and measurement instruments for
an emission test.
(4) Perform pre-test procedures to verify proper operation of
certain equipment and analyzers.
(5) Record pre-test data.
(6) Start or restart the engine and sampling systems.
(7) Sample emissions throughout the duty cycle.
(8) Record post-test data.
(9) Perform post-test procedures to verify proper operation of
certain equipment and analyzers.
(10) Weigh PM samples.
(b) A laboratory emission test generally consists of measuring
emissions and other parameters while an engine follows one or more duty
cycles that are specified in the standard-setting part. There are two
general types of duty cycles:
(1) Transient cycles. Transient duty cycles are typically specified
in the standard-setting part as a second-by-second sequence of speed
commands and torque (or power) commands. Operate an engine over a
transient cycle such that the speed and torque of the engine's primary
output shaft follows the target values. Proportionally sample emissions
and other parameters and use the calculations in subpart G of this part
to calculate emissions. Start a transient test according to the
standard-setting part, as follows:
(i) A cold-start transient cycle where you start to measure
emissions just before starting a cold engine.
(ii) A hot-start transient cycle where you start to measure
emissions just before starting a warmed-up engine.
(iii) A hot running transient cycle where you start to measure
emissions after an engine is started, warmed up, and running.
(2) Steady-state cycles. Steady-state duty cycles are typically
specified in the standard-setting part as a list of discrete operating
points (modes), where each operating point has one value of a speed
command and one value of a torque (or power) command. Ramped-modal
cycles for steady-state testing also list test times for each mode and
ramps of speed and torque to follow between modes. Start a steady-state
cycle as a hot running test, where you start to measure emissions after
an engine is started, warmed up and running. You may run a steady-state
duty cycle as a discrete-mode cycle or a ramped-modal cycle, as
follows:
(i) Discrete-mode cycles. Before emission sampling, stabilize an
engine at the first discrete mode. Sample emissions and other
parameters for that mode and then stop emission sampling. Record mean
values for that mode, and then stabilize the engine at the next mode.
Continue to sample each mode discretely and calculate weighted emission
results according to the standard-setting part.
(ii) Ramped-modal cycles. Perform ramped-modal cycles similar to
the way you would perform transient cycles, except that ramped-modal
cycles involve mostly steady-state engine operation. Perform a ramped-
modal cycle as a sequence of second-by-second speed commands and torque
(or power) commands.Proportionally sample emissions and other
parameters during the cycle and use the calculations in subpart G of
this part to calculate emissions.
(c) Other subparts in this part identify how to select and prepare
an engine for testing (subpart E), how to perform the required engine
service accumulation (subpart E), and how to calculate emission results
(subpart G).
(d) Subpart J of this part describes how to perform field testing.

Sec. 1065.510 Engine mapping.

(a) Scope and frequency. An engine map is a data set that consists
of a series of paired data points that represent the maximum brake
torque versus engine speed, measured at the engine's primary output
shaft. Map your engine while it is connected to a dynamometer.
Configure any auxiliary work inputs and outputs such as hybrid, turbo-
compounding, or thermoelectric systems to represent their in-use
configurations, and use the same configuration for emission testing.
See Figure 1 of Sec. 1065.210. This may involve configuring initial
states of charge and rates and times of auxiliary-work inputs and
outputs. We recommend that you contact the Designated Compliance
Officer before testing to determine how you should configure any
auxiliary-work inputs and outputs. Use the most recent engine map to
transform a normalized duty cycle from the standard-setting part to a
reference duty cycle specific to your engine. Normalized duty cycles
are specified in the standard-setting part. You may update an engine
map at any time by repeating the engine-mapping procedure. You must map
or re-map an engine before a test if any of the following apply:
(1) If you have not performed an initial engine map.
(2) If the atmospheric pressure near the engine's air inlet is not
within ±5 kPa of the atmospheric pressure recorded at the
time of the last engine map.
(3) If the engine or emission-control system has undergone changes
that might affect maximum torque performance. This includes changing
the configuration of auxiliary work inputs and outputs.
(4) If you capture an incomplete map on your first attempt or you
do not complete a map within the specified time tolerance. You may
repeat mapping as often as necessary to capture a complete map within
the specified time.
(b) Mapping variable-speed engines. Map variable-speed engines as
follows:
(1) Record the atmospheric pressure.
(2) Warm up the engine by operating it. We recommend operating the
engine at any speed and at approximately 75% of the its expected
maximum power. Continue the warm-up until either the

[[Page 40562]]

engine coolant, block, or head absolute temperature is within < plus-
minus>2% of its mean value for at least 2 min or until the engine
thermostat controls engine temperature.
(3) Operate the engine at its warm idle speed.
(4) Set operator demand to maximum and control engine speed at (95
±1)% of its warm idle speed for at least 15 seconds. For
engines with reference duty cycles whose lowest speed is greater than
warm idle speed, you may start the map at (95 ±1)% of the
lowest reference speed.
(5) Perform one of the following:
(i) For any engine subject only to steady-state duty cycles (i.e.,
discrete-mode or ramped-modal), you may perform an engine map by using
discrete speeds. Select at least 20 evenly spaced setpoints between
warm idle and the highest speed above maximum mapped power at which (50
to 75)% of maximum power occurs. If this highest speed is unsafe or
unrepresentative (e.g, for ungoverned engines), use good engineering
judgment to map up to the maximum safe speed or the maximum
representative speed. At each setpoint, stabilize speed and allow
torque to stabilize. Record the mean speed and torque at each setpoint.
We recommend that you stabilize an engine for at least 15 seconds at
each setpoint and record the mean feedback speed and torque of the last
(4 to 6) seconds. Use linear interpolation to determine intermediate
speeds and torques. Use this series of speeds and torques to generate
the power map as described in paragraph (e) of this section.
(ii) For any variable-speed engine, you may perform an engine map
by using a continuous sweep of speed by continuing to record the mean
feedback speed and torque at 1 Hz or more frequently and increasing
speed at a constant rate such that it takes (4 to 6) min to sweep from
95% of warm idle to the highest speed above maximum power at which (50
to 75)% of maximum power occurs. If this highest speed is unsafe or
unrepresentative (e.g, for ungoverned engines), use good engineering
judgment to map up to the maximum safe speed or the maximum
representative speed. Stop recording after you complete the sweep. From
the series of mean speed and maximum torque values, use linear
interpolation to determine intermediate values. Use this series of
speeds and torques to generate the power map as described in paragraph
(e) of this section.
(c) Negative torque mapping. If your engine is subject to a
reference duty cycle that specifies negative torque values, generate a
motoring map by any of the following procedures:
(1) Multiply the positive torques from your map by -40%. Use linear
interpolation to determine intermediate values.
(2) Map the amount of negative torque required to motor the engine
by repeating paragraph (b) of this section with minimum operator
demand.
(3) Determine the amount of negative torque required to motor the
engine at the following two points: At warm idle and at the highest
speed above maximum power at which (50 to 75)% of maximum power occurs.
If this highest speed is unsafe or unrepresentative (e.g, for
ungoverned engines), use good engineering judgment to map up to the
maximum safe speed or the maximum representative speed. Operate the
engine at these two points at minimum operator demand. Use linear
interpolation to determine intermediate values.
(d) Mapping constant-speed engines. For constant-speed engines,
generate a map as follows:
(1) Record the atmospheric pressure.
(2) Warm up the engine by operating it. We recommend operating the
engine at approximately 75% of the engine's expected maximum power.
Continue the warm-up until either the engine coolant, block, or head
absolute temperature is within ±2% of its mean value for at
least 2 min or until the engine thermostat controls engine temperature.
(3) You may operate the engine with a production constant-speed
governor or simulate a constant-speed governor by controlling engine
speed with an operator demand control system described in Sec.
1065.110. Use either isochronous or speed-droop governor operation, as
appropriate.
(4) With the governor or simulated governor controlling speed using
operator demand, operate the engine at no-load governed speed (at high
speed, not low idle) for at least 15 seconds.
(5) Record at 1 Hz the mean of feedback speed and torque. Use the
dynamometer to increase torque at a constant rate. Unless the standard-
setting part specifies otherwise, complete the map such that it takes
(2 to 4) min to sweep from no-load governed speed to the lowest speed
below maximum mapped power at which the engine develops (85-95)% of
maximum mapped power. You may map your engine to lower speeds. Stop
recording after you complete the sweep. Use this series of speeds and
torques to generate the power map as described in paragraph (e) of this
section.
(e) Power mapping. For all engines, create a power-versus-speed map
by transforming torque and speed values to corresponding power values.
Use the mean values from the recorded map data. Do not use any
interpolated values. Multiply each torque by its corresponding speed
and apply the appropriate conversion factors to arrive at units of
power (kW).
(f) Measured and declared test speeds and torques. You may use test
speeds and torques that you declare instead of measured speeds and
torques if you declare them before engine mapping and they meet the
criteria in this paragraph (f). Otherwise, you must use measured speed
and torque.
(1) Measured speeds and torques. Determine the applicable measured
speeds and torques according to Sec. 1065.610:
(i) Measured maximum test speed for variable-speed engines.
(ii) Measured maximum test torque for constant-speed engines.
(iii) Measured ``A'', ``B'', and ``C'' speeds for steady-state
tests.
(iv) Measured intermediate speed for steady-state tests.
(2) Required declared speeds. You must declare the following
speeds:
(i) Warmed-up, low-idle speed for variable-speed engines. Declare
this speed in a way that is representative of in-use operation. For
example, if your engine is typically connected to an automatic
transmission or a hydrostatic transmission, declare this speed at the
idle speed at which your engine operates when the transmission is
engaged.
(ii) Warmed-up, no-load, high-idle speed for constant-speed
engines.
(3) Optional declared speeds. You may declare an enhanced idle
speed according to Sec. 1065.610. You may use a declared value for any
of the following as long as the declared value is within (97.5 to
102.5)% of its corresponding measured value:
(i) Measured maximum test speed for variable-speed engines.
(ii) Measured intermediate speed for steady-state tests.
(iii) Measured ``A'', ``B'', and ``C'' speeds for steady-state
tests.
(4) Declared torques. You may declare an enhanced idle torque
according to Sec. 1065.610. You may declare maximum test torque as
long as it is within (95 to 100)% of the measured value.
(g) Other mapping procedures. You may use other mapping procedures
if you believe the procedures specified in this section are unsafe or
unrepresentative for your engine. Any alternate techniques must satisfy
the intent of the specified mapping

[[Page 40563]]

procedures, which is to determine the maximum available torque at all
engine speeds that occur during a duty cycle. Report any deviations
from this section's mapping procedures.

Sec. 1065.512 Duty cycle generation.

(a) The standard-setting part defines applicable duty cycles in a
normalized format. A normalized duty cycle consists of a sequence of
paired values for speed and torque or for speed and power.
(b) Transform normalized values of speed, torque, and power using
the following conventions:
(1) Engine speed for variable-speed engines. For variable-speed
engines, normalized speed may be expressed as a percentage between idle
speed and maximum test speed, f_ntest, or speed may be
expressed by referring to a defined speed by name, such as warm idle,''
``intermediate speed,'' or ``A,'' ``B,'' or ``C'' speed. Section
1065.610 describes how to transform these normalized values into a
sequence of reference speeds, f_nref. Note that the cycle-
validation criteria in Sec. 1065.514 allow an engine to govern itself
at its in-use idle speed. This allowance permits you to test engines
with enhanced-idle devices and to simulate the effects of transmissions
such as automatic transmissions.
(2) Engine torque for variable-speed engines. For variable-speed
engines, normalized torque is expressed as a percentage of the mapped
torque at the corresponding reference speed. Section 1065.610 describes
how to transform normalized torques into a sequence of reference
torques, T_ref. Section 1065.610 also describes under what
conditions you may command T_ref greater than the reference
torque you calculated from a normalized duty cycle. This provision
permits you to command T_ref values representing curb-idle
transmission torque (CITT).
(3) Engine torque for constant-speed engines. For constant-speed
engines, normalized torque is expressed as a percentage of maximum test
torque, Ttest. Section 1065.610 describes how to transform normalized
torques into a sequence of reference torques, T_ref. Section
1065.610 also describes under what conditions you may command
T_ref greater than 0 N[middot]m when a normalized duty cycle
specifies a 0% torque command.
(4) Engine power. For all engines, normalized power is expressed as
a percentage of mapped power at maximum test speed, f_ntest.
Section 1065.610 describes how to transform these normalized values
into a sequence of reference powers, P_ref. You may convert
these reference powers to reference speeds and torques for operator
demand and dynamometer control.
(c) For variable-speed engines, command reference speeds and
torques sequentially to perform a duty cycle. Issue speed and torque
commands at a frequency of at least 5 Hz for transient cycles and at
least 1 Hz for steady-state cycles (i.e., discrete-mode and ramped-
modal). For transient cycles, linearly interpolate between the 1 Hz
reference values specified in the standard-setting part to determine
the 5 Hz reference speeds and torques. During an emission test, record
the 1 Hz mean values of the reference speeds and torques and the
feedback speeds and torques. Use these recorded values to calculate
cycle-validation statistics and total work.
(d) For constant-speed engines, operate the engine with the same
production governor you used to map the engine in Sec. 1065.525 or
simulate the in-use operation of a governor the same way you simulated
it to map the engine in Sec. 1065.525. Command reference torque values
sequentially to perform a duty cycle. Issue torque commands at a
frequency of at least 5 Hz for transient cycles and at least 1 Hz for
steady-state cycles (i.e, discrete-mode, ramped-modal). For transient
cycles, linearly interpolate between the 1 Hz reference values
specified in the standard-setting part to determine the 5 Hz reference
torque values. During an emission test, record the 1 Hz mean values of
the reference torques and the feedback speeds and torques. Use these
recorded values to calculate cycle-validation statistics and total
work.
(e) You may perform practice duty cycles with the test engine to
optimize operator demand and dynamometer controls to meet the cycle-
validation criteria specified in Sec. 1065.514.

Sec. 1065.514 Cycle-validation criteria.

This section describes how to determine if the engine's operation
during the test adequately matched the reference duty cycle. This
section applies only to speed, torque, and power from the engine's
primary output shaft. Other work inputs and outputs are not subject to
cycle-validation criteria. For any data required in this section, use
the duty cycle reference and feedback values that you recorded during a
test interval.
(a) Testing performed by EPA. Our tests must meet the
specifications of paragraph (g) of this section, unless we determine
that failing to meet the specifications is related to engine
performance rather than to shortcomings of the dynamometer or other
laboratory equipment.
(b) Testing performed by manufacturers. Emission tests that meet
the specifications of paragraph (g) of this section satisfy the
standard-setting part's requirements for duty cycles. You may ask to
use a dynamometer or other laboratory equipment that cannot meet those
specifications. We will approve your request as long as using the
alternate equipment does not affect your ability to show compliance
with the applicable emission standards.
(c) Time-alignment. Because time lag between feedback values and
the reference values may bias cycle-validation results, you may advance
or delay the entire sequence of feedback engine speed and torque pairs
to synchronize them with the reference sequence.
(d) Calculating work. Before calculating work values, omit any
points recorded during engine cranking and starting. Cranking and
starting includes any time when an engine starter is engaged, any time
when the engine is motored with a dynamometer for the sole purpose of
starting the engine, and any time during operation before reaching idle
speed. See Sec. 1065.525(a) and (b) for more information about engine
cranking. After omitting points recorded during engine cranking and
starting, but before omitting any points under paragraph (e) of this
section, calculate total work, W, based on the feedback values and
reference work, W_ref, based on the reference values, as
described in Sec. 1065.650.
(e) Omitting additional points. Besides engine cranking, you may
omit additional points from cycle-validation statistics as described in
the following table:

[[Page 40564]]

Table 1 of Sec. 1065.514.--Permissible Criteria for Omitting Points
From Duty-Cycle Regression Statistics
------------------------------------------------------------------------
When operator demand is at
its. . . you may omit. . . if. . .
------------------------------------------------------------------------
For reference duty cycles that are specified in terms of speed and
torque (fnref, Tref).
------------------------------------------------------------------------
minimum..................... power and torque.... Tref < 0%
(motoring).
minimum..................... power and speed..... fnref = 0% (idle)
and Tref = 0%
(idle) and Tref-(2%
\.\ Tmax mapped) <
T < Tref + (2% \.\
Tmax mapped).
minimum..................... power and either fn > fnref or T >
torque or speed. Tref but not if fn
> fnref and T >
Tref.
maximum..................... power and either fn < fnref or T <
torque or speed. Tref but not if fn
< fnef and T <
Tref.
-----------------------------
For reference duty cycles that are specified in terms of speed and power
(fnref, Pref).
------------------------------------------------------------------------
minimum..................... power and torque.... Pref < 0%
(motoring).
minimum..................... power and speed..... fnref = 0% (idle)
and Pref = 0 %
(idle) and Pref -
(2% \.\ Pmax
mapped) < P < Pref
+ (2% \.\ Pmax
mapped).
minimum..................... power and either fn > fnref or P >
torque or speed. Pref but not if fn
> fnref and P >
Pref.
maximum..................... power and either fn < fnref or P <
torque or speed. Pref but not if fn
< fnef and P <
Pref.
------------------------------------------------------------------------

(f) Statistical parameters. Use the remaining points to calculate
regression statistics described in Sec. 1065.602. Round calculated
regression statistics to the same number of significant digits as the
criteria to which they are compared. Refer to Table 2 of Sec. 1065.514
for the criteria. Calculate the following regression statistics :
(1) Slopes for feedback speed, a_1fn, feedback torque,
a_1T, and feedback power a_1P.
(2) Intercepts for feedback speed, a_0fn, feedback
torque, a_0T, and feedback power a_0P.
(3) Standard estimates of error for feedback speed,
SEE_fn, feedback torque, SE_T, and feedback power
SEE_P.
(4) Coefficients of determination for feedback speed,
r2_fn, feedback torque, r2
_T, and feedback power r2 _p.
(g) Cycle-validation criteria. Unless the standard-setting part
specifies otherwise, use the following criteria to validate a duty
cycle:
(1) For variable-speed engines, apply all the statistical criteria
in Table 2 of this section.
(2) For constant-speed engines, apply only the statistical criteria
for torque in the Table 2 of this section.

Table 2 of Sec. 1065.514.--Default Statistical Criteria for Validating Duty Cycles
----------------------------------------------------------------------------------------------------------------
Parameter Speed Torque Power
----------------------------------------------------------------------------------------------------------------
Slope, a1............................ 0.950 < = a1 < 1.030.... 0.830 < = a1 < 1.030.... 0.830 < = a1 < 1.030.
Absolute value of intercept, < = 10% of warm idle.... < = 2.0% of maximum < = 2.0% of maximum
[bond]a0[bond]. mapped torque. mapped power.
Standard error of estimate, SEE...... < = 5.0% of maximum test < = 10% of maximum < = 10% of maximum
speed. mapped torque. mapped power.
Coefficient of determination, r2..... >= 0.970............... >= 0.850............... >= 0.910.
----------------------------------------------------------------------------------------------------------------

Sec. 1065.520 Pre-test verification procedures and pre-test data
collection.

(a) If your engine must comply with a PM standard, follow the
procedures for PM sample preconditioning and tare weighing according to
Sec. 1065.590.
(b) Unless the standard-setting part specifies different values,
verify that ambient conditions are within the following tolerances
before the test:
(1) Ambient temperature of (20 to 30) [deg]
C.
(2) Atmospheric pressure of (80.000 to 103.325) kPa and within
±5% of the value recorded at the time of the last engine
map.
(3) Dilution air as specified in Sec. 1065.140(b).
(c) You may test engines at any intake-air humidity, and we may
test engines at any intake-air humidity.
(d) Verify that auxiliary-work inputs and outputs are configured as
they were during engine mapping, as described inSec. 1065.510(a).
(e) You may perform a final calibration of the speed, torque, and
proportional-flow control systems, which may include performing
practice duty cycles.
(f) You may perform the following recommended procedure to
precondition sampling systems:
(1) Start the engine and use good engineering judgment to bring it
to 100% torque at any speed above its peak-torque speed.
(2) Operate any dilution systems at their expected flow rates.
Prevent aqueous condensation in the dilution systems.
(3) Operate any PM sampling systems at their expected flow rates.
(4) Sample PM for at least 10 min using any sample media. You may
change sample media during preconditioning. You may discard
preconditioning samples without weighing them.
(5) You may purge any gaseous sampling systems during
preconditioning.
(6) You may conduct calibrations or verifications on any idle
equipment or analyzers during preconditioning.
(7) Proceed with the test sequence described in Sec.
1065.530(a)(1).
(g) After the last practice or preconditioning cycle before an
emission test, verify the amount of contamination in the HC sampling
system as follows:
(1) Select the HC analyzer range for measuring the flow-weighted
mean concentration expected at the HC standard.
(2) Zero the HC analyzer at the analyzer zero or sample port. Note
that FID zero and span balance gases may be any combination of purified
air or purified nitrogen that meets the

[[Page 40565]]

specifications of Sec. 1065.750. We recommend FID analyzer zero and
span gases that contain approximately the flow-weighted mean
concentration of O₂ expected during testing.
(3) Span the HC analyzer using span gas introduced at the analyzer
span or sample port. Span on a carbon number basis of one
(C₁). For example, if you use a C₃H₈
span gas of concentration 200 [mu]mol/mol, span the FID to respond with
a value of 600 [mu]mol/mol.
(4) Overflow zero gas at the HC probe or into a fitting between the
HC probe and its transfer line.
(5) Measure the HC concentration in the sampling system, as
follows:
(i) For continuous sampling, record the mean HC concentration as
overflow zero air flows.
(ii) For batch sampling, fill the sample medium and record its mean
HC concentration.
(6) Record this value as the initial HC concentration,
x_HCinit, and use it to correct measured values as described
in Sec. 1065.660.
(7) If x_HCinit exceeds the greatest of the following
values, determine the source of the contamination and take corrective
action, such as purging the system during an additional preconditioning
cycle or replacing contaminated portions:
(i) 2% of the flow-weighted mean concentration expected at the
standard.
(ii) 2% of the flow-weighted mean concentration measured during
testing.
(iii) For any compression-ignition engines, any two-stroke spark
ignition engines, or 4-stroke spark-ignition engines that are less than
19 kW, 2 [mu]mol/mol.
(8) If corrective action does not resolve the deficiency, you may
request to use the contaminated system as an alternate procedure under
Sec. 1065.10.

Sec. 1065.525 Engine starting, restarting, and shutdown.

(a) Start the engine using one of the following methods:
(1) Start the engine as recommended in the owners manual using a
production starter motor and adequately charged battery or a suitable
power supply.
(2) Use the dynamometer to start the engine. To do this, motor the
engine within ±25% of its typical in-use cranking speed.
Stop cranking within 1 second of starting the engine.
(b) If the engine does not start after 15 seconds of cranking, stop
cranking and determine why the engine failed to start, unless the
owners manual or the service-repair manual describes the longer
cranking time as normal.
(c) Respond to engine stalling with the following steps:
(1) If the engine stalls during warm-up before emission sampling
begins, restart the engine and continue warm-up.
(2) If the engine stalls during preconditioning before emission
sampling begins, restart the engine and restart the preconditioning
sequence.
(3) If the engine stalls at any time after emission sampling begins
for a transient test or ramped-modal cycle test, the test is void.
(4) If the engine stalls at any time after emission sampling begins
for a discrete mode in a discrete-mode duty cycle test, void the test
or perform the following steps to continue the test:
(i) Restart the engine.
(ii) Use good engineering judgment to restart the test sequence
using the appropriate steps in Sec. 1065.530(b)
(iii) Precondition the engine at the previous discrete mode for a
similar amount of time compared with how long it was initially run.
(iv) Advance to the mode at which the engine stalled and continue
with the duty cycle as specified in the standard-setting part.
(v) Complete the remainder of the test according to the
requirements in this subpart.
(d) Shut down the engine according to the manufacturer's
specifications.

Sec. 1065.530 Emission test sequence.

(a) Time the start of testing as follows:
(1) Perform one of the following if you precondition sampling
systems as described in Sec. 1065.520(f):
(i) For cold-start duty cycles, shut down the engine. Unless the
standard-setting part specifies that you may only perform a natural
engine cooldown, you may perform a forced engine cooldown. Use good
engineering judgment to set up systems to send cooling air across the
engine, to send cool oil through the engine lubrication system, to
remove heat from coolant through the engine cooling system, and to
remove heat from an exhaust aftertreatment system. In the case of a
forced aftertreatment cooldown, good engineering judgment would
indicate that you not start flowing cooling air until the
aftertreatment system has cooled below its catalytic activation
temperature. For platinum-group metal catalysts, this temperature is
about 200 [deg]C. Once the aftertreatment system has naturally cooled
below its catalytic activation temperature, good engineering judgment
would indicate that you use clean air with a temperature of at least 15
[deg]C, and direct the air through the aftertreatment system in the
normal direction of exhaust flow. Do not use any cooling procedure that
results in unrepresentative emissions (see Sec. 1065.10(c)(1)). You
may start a cold-start duty cycle when the temperatures of an engine's
lubricant, coolant, and aftertreatment systems are all between (20 and
30) [deg]C.
(ii) For hot-start emission measurements, shut down the engine.
Start a hot-start duty cycle within 20 min of engine shutdown.
(iii) For testing that involves hot-stabilized emission
measurements, such as any steady-state testing, you may continue to
operate the engine at f_ntest and 100% torque if that is the
first operating point. Otherwise, operate the engine at warm, idle or
the first operating point of the duty cycle. In any case, start the
emission test within 10 min after you complete the preconditioning
procedure.
(2) For all other testing, perform one of the following:
(i) For cold-start duty cycles, prepare the engine according to
paragraph (a)(1)(i) of this section.
(ii) For hot-start emission measurements, first operate the engine
at any speed above peak-torque speed and at (65 to 85) % of maximum
mapped power until either the engine coolant, block, or head absolute
temperature is within ±2% of its mean value for at least 2
min or until the engine thermostat controls engine temperature. Shut
down the engine. Start the duty cycle within 20 min of engine shutdown.
(iii) For testing that involves hot-stabilized emission
measurements, bring the engine either to warm idle or the first
operating point of the duty cycle. Start the test within 10 min of
achieving temperature stability. Determine temperature stability either
as the point at which the engine coolant, block, or head absolute
temperature is within ±2% of its mean value for at least 2
min, or as the point at which the engine thermostat controls engine
temperature.
(b) Take the following steps before emission sampling begins:
(1) For batch sampling, connect clean storage media, such as
evacuated bags or tare-weighed filters.
(2) Start all measurement instruments according to the instrument
manufacturer's instructions and using good engineering judgment.
(3) Start dilution systems, sample pumps, cooling fans, and the
data-collection system.
(4) Pre-heat or pre-cool heat exchangers in the sampling system to
within their operating temperature tolerances for a test.
(5) Allow heated or cooled components such as sample lines,

[[Page 40566]]

filters, chillers, and pumps to stabilize at their operating
temperatures.
(6) Verify that there are no significant vacuum-side leaks
according to Sec. 1065.345.
(7) Adjust the sample flow rates to desired levels, using bypass
flow, if desired.
(8) Zero or re-zero any electronic integrating devices, before the
start of any test interval.
(9) Select gas analyzer ranges. You may use analyzers that
automatically switch ranges during a test only if switching is
performed by changing the span over which the digital resolution of the
instrument is applied. During a test you may not switch the gains of an
analyzer's analog operational amplifier(s).
(10) Zero and span all continuous analyzers using NIST-traceable
gases that meet the specifications of Sec. 1065.750. Span FID
analyzers on a carbon number basis of one (1), C₁. For
example, if you use a C₃H₈ span gas of
concentration 200 [mu]mol/mol, span the FID to respond with a value of
600 [mu]mol/mol.
(11) We recommend that you verify gas analyzer response after
zeroing and spanning by flowing a calibration gas that has a
concentration near one-half of the span gas concentration. Based on the
results and good engineering judgment, you may decide whether or not to
re-zero, re-span, or re-calibrate a gas analyzer before starting a
test.
(12) If you correct for dilution air background concentrations of
engine exhaust constituents, start measuring and recording background
concentrations.
(c) Start testing as follows:
(1) If an engine is already running and warmed up, and starting is
not part of the duty cycle, perform the following for the various duty
cycles.
(i) Transient and steady-state ramped-modal cycles. Simultaneously
start running the duty cycle, sampling exhaust gases, recording data,
and integrating measured values.
(ii) Steady-state discrete-mode cycles. Control speed and torque to
the first mode in the test cycle. Follow the instructions in the
standard-setting part to determine how long to stabilize engine
operation at each mode and how long to sample emissions at each mode.
(2) If engine starting is part of the duty cycle, initiate data
logging, sampling of exhaust gases, and integrating measured values
before attempting to start the engine. Initiate the duty cycle when the
engine starts.
(d) At the end of the test interval, continue to operate all
sampling and dilution systems to allow the sampling system's response
time to elapse. Then stop all sampling and recording, including the
recording of background samples. Finally, stop any integrating devices
and indicate the end of the duty cycle in the recorded data.
(e) Shut down the engine if you have completed testing or if it is
part of the duty cycle.
(f) If testing involves another duty cycle after a soak period with
the engine off, start a timer when the engine shuts down, and repeat
the steps in paragraphs (b) through (e) of this section as needed.
(g) Take the following steps after emission sampling is complete:
(1) For any proportional batch sample, such as a bag sample or PM
sample, verify that proportional sampling was maintained according to
Sec. 1065.545. Void any samples that did not maintain proportional
sampling according to Sec. 1065.545.
(2) Place any used PM samples into covered or sealed containers and
return them to the PM-stabilization environment. Follow the PM sample
post-conditioning and total weighing procedures in Sec. 1065.595.
(3) As soon as practical after the duty cycle is complete but no
later than 30 minutes after the duty cycle is complete, perform the
following:
(i) Zero and span all batch gas analyzers.
(ii) Analyze any gaseous batch samples, including background
samples.
(4) After quantifying exhaust gases, verify drift as follows:
(i) For batch and continuous gas analyzers, record the mean
analyzer value after stabilizing a zero gas to the analyzer.
Stabilization may include time to purge the analyzer of any sample gas,
plus any additional time to account for analyzer response.
(ii) Record the mean analyzer value after stabilizing the span gas
to the analyzer. Stabilization may include time to purge the analyzer
of any sample gas, plus any additional time to account for analyzer
response.
(iii) Use these data to validate and correct for drift as described
in Sec. 1065.550.
(h) Determine whether or not the test meets the cycle-validation
criteria in Sec. 1065.514.
(1) If the criteria void the test, you may retest using the same
denormalized duty cycle, or you may re-map the engine, denormalize the
reference duty cycle based on the new map and retest the engine using
the new denormalized duty cycle.
(2) If the criteria void the test for a constant-speed engine only
during commands of maximum test torque, you may do the following:
(i) Determine the first and last feedback speeds at which maximum
test torque was commanded.
(ii) If the last speed is greater than or equal to 90% of the first
speed, the test is void. You may retest using the same denormalized
duty cycle, or you may re-map the engine, denormalize the reference
duty cycle based on the new map and retest the engine using the new
denormalized duty cycle.
(iii) If the last speed is less than 90% of the first speed, reduce
maximum test torque by 5%, and proceed as follows:
(A) Denormalize the entire duty cycle based on the reduced maximum
test
torque according to Sec. 1065.512.
(B) Retest the engine using the denormalized test cycle that is
based on the reduced maximum test torque.
(C) If your engine still fails the cycle criteria, reduce the
maximum test torque by another 5% of the original maximum test torque.
(D) If your engine fails after repeating this procedure four times,
such that your engine still fails after you have reduced the maximum
test torque by 20% of the original maximum test torque, notify us and
we will consider specifying a more appropriate duty cycle for your
engine under the provisions of Sec. 1065.10(c).

Sec. 1065.545 Validation of proportional flow control for batch
sampling.

For any proportional batch sample such as a bag or PM filter,
demonstrate that proportional sampling was maintained using one of the
following, noting that you may omit up to 5% of the total number of
data points as outliers:
(a) For any pair of flow meters, use the 1 Hz (or more frequently)
recorded sample and total flow rates with the statistical calculations
in Sec. 1065.602. Determine the standard error of the estimate, SEE,
of the sample flow rate versus the total flow rate. For each test
interval, demonstrate that SEE was less than or equal to 3.5% of the
mean sample flow rate.
(b) For any pair of flow meters, use the 1 Hz (or more frequently)
recorded sample and total flow rates to demonstrate that each flow rate
was constant within ±2.5% of its respective mean or target
flow rate. You may use the following options instead of recording the
respective flow rate of each type of meter:
(1) Critical-flow venturi option. For critical-flow venturis, you
may use the 1 Hz (or more frequently) recorded venturi-inlet
conditions. Demonstrate that the flow density at the venturi inlet

[[Page 40567]]

was constant within ±2.5% of the mean or target density over
each test interval. For a CVS critical-flow venturi, you may
demonstrate this by showing that the absolute temperature at the
venturi inlet was constant within ±4% of the mean or target
absolute temperature over each test interval.
(2) Positive-displacement pump option. You may use the 1 Hz (or
more frequently) recorded pump-inlet conditions. Demonstrate that the
density at the pump inlet was constant within ±2.5% of the
mean or target density over each test interval. For a CVS pump, you may
demonstrate this by showing that the absolute temperature at the pump
inlet was constant within ±2% of the mean or target absolute
temperature over each test interval.
(c) Using good engineering judgment, demonstrate with an
engineering analysis that the proportional-flow control system
inherently ensures proportional sampling under all circumstances
expected during testing. For example, you might use CFVs for both
sample flow and total flow and demonstrate that they always have the
same inlet pressures and temperatures and that they always operate
under critical-flow conditions.

Sec. 1065.550 Gas analyzer range validation, drift validation, and
drift correction.

(a) Range validation. If an analyzer operated above 100% of its
range at any time during the test, perform the following steps:
(1) For batch sampling, re-analyze the sample using the lowest
analyzer range that results in a maximum instrument response below
100%. Report the result from the lowest range from which the analyzer
operates below 100% of its range for the entire test.
(2) For continuous sampling, repeat the entire test using the next
higher analyzer range. If the analyzer again operates above 100% of its
range, repeat the test using the next higher range. Continue to repeat
the test until the analyzer operates at less than 100% of its range for
the entire test.
(b) Drift validation and drift correction. Calculate two sets of
brake-specific emission results. Calculate one set using the data
before drift correction and the other set after correcting all the data
for drift according to Sec. 1065.672. Use the two sets of brake-
specific emission results as follows:
(1) If the difference between the corrected and uncorrected brake-
specific emissions are within ±4% of the uncorrected results
for all regulated emissions, the test is validated for drift. If not,
the entire test is void.
(2) If the test is validated for drift, you must use only the
drift-corrected emission results when reporting emissions, unless you
demonstrate to us that using the drift-corrected results adversely
affects your ability to demonstrate whether or not your engine complies
with the applicable standards.

Sec. 1065.590 PM sample preconditioning and tare weighing.

Before an emission test, take the following steps to prepare PM
samples and equipment for PM measurements:
(a) Make sure the balance and PM-stabilization environments meet
the periodic verifications in Sec. 1065.390.
(b) Visually inspect unused sample media (such as filters) for
defects.
(c) To handle PM samples, use electrically grounded tweezers or a
grounding strap, as described in Sec. 1065.190.
(d) Place unused sample media in one or more containers that are
open to the PM-stabilization environment. If you are using filters, you
may place them in the bottom half of a filter cassette.
(e) Stabilize sample media in the PM-stabilization environment.
Consider an unused sample medium stabilized as long as it has been in
the PM-stabilization environment for a minimum of 30 min, during which
the PM-stabilization environment has been within the specifications of
Sec. 1065.190.
(f) Weigh the sample media automatically or manually, as follows:
(1) For automatic weighing, follow the automation system
manufacturer's instructions to prepare samples for weighing. This may
include placing the samples in a special container.
(2) For manual weighing, use good engineering judgment to determine
if substitution weighing is necessary to show that an engine meets the
applicable standard. You may follow the substitution weighing procedure
in paragraph (j) of this section, or you may develop your own
procedure.
(g) Correct the measured weight for buoyancy as described in Sec.
1065.690. These buoyancy-corrected values are the tare masses of the PM
samples.
(h) You may repeat measurements to determine mean masses. Use good
engineering judgment to exclude outliers and calculate mean mass
values.
(i) If you use filters as sample media, load unused filters that
have been tare-weighed into clean filter cassettes and place the loaded
cassettes in a covered or sealed container before taking them to the
test cell for sampling. We recommend that you keep filter cassettes
clean by periodically washing or wiping them with a compatible solvent
applied using a lint-free cloth. Depending upon your cassette material,
ethanol (C₂H₅OH) might be an acceptable solvent.
Your cleaning frequency will depend on your engine's level of PM and HC
emissions.
(j) Substitution weighing involves measurement of a reference
weight before and after each weighing of a PM sample. While
substitution weighing requires more measurements, it corrects for a
balance's zero-drift and it relies on balance linearity only over a
small range. This is most advantageous when quantifying net PM masses
that are less than 0.1% of the sample medium's mass. However, it may
not be advantageous when net PM masses exceed 1% of the sample medium's
mass. The following steps are an example of substitution weighing:
(1) Use electrically grounded tweezers or a grounding strap, as
described in Sec. 1065.190.
(2) Use a static neutralizer as described in Sec. 1065.190 to
minimize static electric charge on any object before it is placed on
the balance pan.
(3) Place on the balance pan a metal calibration weight that has a
similar mass to that of the sample medium and meets the specifications
for calibration weights in Sec. 1065.790. If you use filters, the
weight's mass should be about (80 to 100) mg for typical 47 mm diameter
filters.
(4) Record the stable balance reading, then remove the calibration
weight.
(5) Weigh an unused sample, record the stable balance reading and
record the balance environment's dewpoint, ambient temperature, and
atmospheric pressure.
(6) Reweigh the calibration weight and record the stable balance
reading.
(7) Calculate the arithmetic mean of the two calibration-weight
readings that you recorded immediately before and after weighing the
unused sample. Subtract that mean value from the unused sample reading,
then add the true mass of the calibration weight as stated on the
calibration-weight certificate. Record this result. This is the unused
sample's tare weight without correcting for buoyancy.
(8) Repeat these substitution-weighing steps for the remainder of
your unused sample media.
(9) Follow the instructions given in paragraphs (g) through (i) of
this section.

Sec. 1065.595 PM sample post-conditioning and total weighing.

(a) Make sure the weighing and PM-stabilization environments have
met the periodic verifications in Sec. 1065.390.
(b) In the PM-stabilization environment, remove PM samples from

[[Page 40568]]

sealed containers. If you use filters, you may remove them from their
cassettes before or after stabilization. When you remove a filter from
a cassette, separate the top half of the cassette from the bottom half
using a cassette separator designed for this purpose.
(c) To handle PM samples, use electrically grounded tweezers or a
grounding strap, as described in Sec. 1065.190.
(d) Visually inspect PM samples. If PM ever contacts the transport
container, cassette assembly, filter-separator tool, tweezers, static
neutralizer, balance, or any other surface, void the measurements
associated with that sample and clean the surface it contacted.
(e) To stabilize PM samples, place them in one or more containers
that are open to the PM-stabilization environment, which is described
in Sec. 1065.190. A PM sample is stabilized as long as it has been in
the PM-stabilization environment for one of the following durations,
during which the stabilization environment has been within the
specifications of Sec. 1065.190:
(1) If you expect that a filter's total surface concentration of PM
will be greater than about 0.473 mm/mm\2\, expose the filter to the
stabilization environment for at least 60 minutes before weighing.
(2) If you expect that a filter's total surface concentration of PM
will be less than about 0.473 mm/mm\2\, expose the filter to the
stabilization environment for at least 30 minutes before weighing.
(3) If you are unsure of a filter's total surface concentration of
PM, expose the filter to the stabilization environment for at least 60
minutes before weighing.
(f) Repeat the procedures in Sec. 1065.590(f) through (i) to weigh
used PM samples. Refer to a sample's post-test mass, after correcting
for buoyancy, as its total mass.
(g) Subtract each buoyancy-corrected tare mass from its respective
buoyancy-corrected total mass. The result is the net PM mass,
m_PM. Use m_PM in emission calculations in Sec.
1065.650.

Subpart G--Calculations and Data Requirements

Sec. 1065.601 Overview.

(a) This subpart describes how to--
(1) Use the signals recorded before, during, and after an emission
test to calculate brake-specific emissions of each regulated
constituent.
(2) Perform calculations for calibrations and performance checks.
(3) Determine statistical values.
(b) You may use data from multiple systems to calculate test
results for a single emission test, consistent with good engineering
judgment. You may not use test results from multiple emission tests to
report emissions. We allow weighted means where appropriate. You may
discard statistical outliers, but you must report all results.
(c) You may use any of the following calculations instead of the
calculations specified in this subpart G:
(1) Mass-based emission calculations prescribed by the
International Organization for Standardization (ISO), according to ISO
8178.
(2) Other calculations that you show are equivalent to within
±0.1% of the brake-specific emission results determined
using the calculations specified in this subpart G.

Sec. 1065.602 Statistics.

(a) Overview. This section contains equations and example
calculations for statistics that are specified in this part. In this
section we use the letter ``y'' to denote a generic measured quantity,
the superscript over-bar ``-`` to denote an arithmetic mean,
and the subscript ``_ref'' to denote the reference quantity
being measured.
(b) Arithmetic mean. Calculate an arithmetic mean, y< =, as follows:
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.022

Example:

N = 3
y₁ = 10.60
y₂ = 11.91
y_N = y₃ = 11.09
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.023

y< = = 11.20

(c) Standard deviation. Calculate the standard deviation for a non-
biased (e.g., N-1) sample, [sigma], as follows:
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.024

Example:

N = 3
y₁ = 10.60
y₂ = 11.91
y_N = y₃ = 11.09
y< = = 11.20
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.025

[sigma]_y = 0.6619

(d) Root mean square. Calculate a root mean square,
rms_y, as follows:
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.026

Example:

N = 3
y₁ = 10.60
y₂ = 11.91
y_N = y₃ = 11.09
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.027

rms_y = 11.21
(e) Accuracy. Calculate an accuracy, as follows, noting that the
are arithmetic means, each determined by repeatedly measuring one
sample of a single reference quantity,y_ref:
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.028

Example:

y_ref = 1800.0
N = 10
[GRAPHIC]
[TIFF OMITTED]
TR13JY05.029

accuracy = [bond]
1800.0 - 1802.5 [bond]
accuracy = 2.5

(f) t-test. Determine if your data passes a t-test by using the
following equations and tables:
(1) For an unpaired t-test, calculate the t statistic and its
number of degrees of freedom, v, as follows:

[GRAPHIC]
[TIFF OMITTED]
TR13JY05.030
[[Continued on page 40569]]

Notices For
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994

Test Procedures for Testing Highway and Nonroad Engines and Omnibus Technical Amendments [[pp. 40519-40568]]

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