Test Procedures for Testing Highway and Nonroad Engines and
Omnibus Technical Amendments
[Federal Register: September 10, 2004 (Volume 69, Number 175)]
[Proposed Rules]
[Page 54945-54994]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10se04-14]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 85, 86, 89, 90, 91, 92, 94, 1039, 1048, 1051, 1065,
and 1068
[AMS-FRL-7803-7]
RIN 2060-AM35
Test Procedures for Testing Highway and Nonroad Engines and
Omnibus Technical Amendments
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of proposed rulemaking.
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Table 1 of Sec. 1065.202.--Data Recording and Control Minimum Frequencies
----------------------------------------------------------------------------------------------------------------
Applicable section Measured values Minimum frequency
----------------------------------------------------------------------------------------------------------------
Sec. 1065.510................. Speed and torque during 1 mean value per step.
an engine step-map.
Sec. 1065.510................. Speed and torque during 1 Hz averages of 5 Hz samp.
an engine sweep-map.
Sec. 1065.514, Sec. 1065.530 Duty cycle reference 5 Hz.
and feedback speeds
and torques for
control and recording.
Sec. 1065.520, Sec. Continuous 1 Hz.
1065.530, Sec. 1065.550. concentrations of raw
or dilute analyzers.
Sec. 1065.520, Sec. Batch concentrations of 1 mean value per test interval.
1065.530, Sec. 1065.550. raw or dilute
analyzers.
Sec. 1065.530, Sec. 1065.545 Diluted exhaust flow 1 Hz.
rate from a CVS with a
heat exchanger.
Sec. 1065.530, Sec. 1065.545 Diluted exhaust flow 5 Hz.
rate from a CVS
without a heat
exchanger.
Sec. 1065.530, Sec. 1065.545 Intake-air, dilution- 5 Hz.
air, or raw-exhaust
flow rate.
Sec. 1065.530, Sec. 1065.545 Sample flow from a CVS 1 Hz.
that has a heat
exchanger.
Sec. 1065.530, Sec. 1065.545 Sample flow from a CVS 5 Hz.
does 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, performance checks, and test-validation criteria
specified in subparts D and F of this part (and subpart J of this part
for field testing). We recommend that you take the following steps to
ensure that your test system performs adequately:
(a) Meet the specifications for individual measurement instruments
in Table 1 of this section. For instruments with multiple ranges, this
applies to all the ranges you use for testing. The accuracy
specifications represent deviations from a true value or a calibration-
standard value.
(b) Sample and record the quantity at the rate specified in Table 1
of this section if your instrument meets the rise time and fall time in
the table. Note that Sec. 1065.308 requires that the product of the
rise time and the frequency to be 5 or greater for continuous-analyzer
systems.
(c) Keep any documentation from instrument manufacturers showing
that instruments meet specifications.
Table 1 of Sec. 1065.205.--Recommended Performance Specifications for Measurement Instruments
----------------------------------------------------------------------------------------------------------------
Complete
system
Measured rise Recording
Measurement instrument quantity time and update Accuracy\a\ Repeatability\a\ Noise\a\
symbol fall frequency
time
----------------------------------------------------------------------------------------------------------------
Engine speed transducer...... fn...... 1 s..... 5 Hz..... 2.0 % of pt. or 1.0 % of pt..... 0.05 % of max
0.5 % of max... 0.25 % of max...
Engine torque transducer..... T....... 1 s..... 5 Hz..... 2.0 % of pt. or 1.0 % of pt..... 0.05 % of max
1.0 % of max... 0.5 % of max....
General pressure transducer p....... 5 s..... 1 Hz..... 2.0 % of pt. or 1.0 % of pt..... 0.1 % of max
(not a part of another 1.0 % of max... 0.50 % of max...
instrument).
Barometer.................... Pbarom.. 50 s.... 0.1 Hz... 50 Pa.......... 25 Pa........... 5 Pa
Temperature sensor for PM- T....... 50 s.... 0.1 Hz... 0.25 [deg]C.... 0.1 [deg]C...... 0.02 [deg]C
stabilization and balance
environments.
Other temperature sensor (not T....... 5 s..... 1 Hz..... 2 [deg]C....... 1 [deg]C........ 0.2 [deg]C
a part of another
instrument).
Dewpoint sensor for PM- Tdew.... 50 s.... 0.1 Hz... 0.25 [deg]C.... 0.1 [deg]C...... 0.02 [deg]C
stabilization and balance
environments.
Other dewpoint sensor........ Tdew.... 50 s.... 0.1 Hz... 1 [deg]C....... 0.5 [deg]C...... 0.1 [deg]C
Fuel flow meter (Fuel m....... 5 s..... 1 Hz..... 2.0 % of pt. or 1.0 % of pt..... 0.5 % of max.
totalizer in parentheses). (N/A)... (N/A).... 1.5 % of max... 0.75 % of max...
Diluted exhaust meter........ n....... 5 s..... 1 Hz..... 2.0 % of pt. or 1.0 % of pt..... 1.0 % of max
1.5 % of max... 0.75 % of max...
Dilution air, inlet air, n....... 1 s..... 5 Hz..... 2.5 % of pt. or 1.25 % of pt.... 1.0 % of max
exhaust, and sample flow 1.5 % of max... 0.75 % of max...
meters.
Constituent concentration, x....... 5 s..... 1 Hz..... 2.0 % of pt.... 1.0 % of pt..... 0.2 % of max
continuous analyzer. 2.0 % of meas.. 1.0 % of meas...
Constituent concentration, x....... N/A..... N/A...... 2.0 % of pt.... 1.0 % of pt..... 0.2 % of max
batch analyzer. 2.0 % of meas.. 1.0 % of meas...
Gravimetric PM balance....... mPM..... N/A..... N/A...... See Sec. 0.25 [mu]g...... 0.1 [mu]g
1065.790.
[[Page 54946]]
Inertial PM balance.......... mPM..... 5 s..... 1 Hz..... 2.0 % of pt.... 1.0 % of pt..... 0.2 % of max.
2.0 % of meas.. 1.0 % of meas...
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a Accuracy, repeatability, and noise are determined with the same collected data, as described in Sec.
1065.305. ``pt.'' refers to a single point at the average value expected during testing at the standard--the
reference value used in Sec. 1065.305; ``max.'' refers to the maximum value expected during testing at the
standard over any test interval, not the maximum of the instrument's range; ``meas'' refers to the flow-
weighted average measured value during any test interval.
Measurement of Engine Parameters and Ambient Conditions
Sec. 1065.210 Speed and torque transducers.
(a) Application. Use instruments as specified in this section to
measure engine speed and torque during engine operation.
(b) Component requirements. We recommend that you use speed and
torque transducers that meet the specifications in Table 1 of Sec.
1065.205. Note that your overall systems for measuring engine speed and
torque must meet the linearity checks in Sec. 1065.307.
(c) Speed. Use a magnetic or optical shaft-position detector with a
resolution of at least 6[deg]
arc, in combination with a frequency
counter that rejects common-mode noise.
(d) 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:
(1) Measure torque by mounting a strain gage in-line between the
engine and dynamometer.
(2) Measure torque by mounting a strain gage on a lever arm
connected to the dynamometer housing.
(3) Calculate torque from internal dynamometer signals, such as
armature current, as long as you calibrate this measurement as
described in Sec. 1065.310.
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 and temperature 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 performance checks in Sec. 1065.315.
(c) Temperature. For PM-balance environments or other precision
temperature measurements, 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 control their internal
temperature or compensate for temperature changes over their expected
operating range. Transducer materials must be compatible with the fluid
being measured. For barometric pressure or other precision pressure
measurements, we recommend either capacitance-type or laser-
interferometer transducers. For other applications, we recommend either
strain gauge 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 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 constituent
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 check in Sec. 1065.307 and the
calibration and performance checks 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 if 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
[[Page 54947]]
length equal to 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. 1065.225 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 a 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 constituent
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 averaging Pitot tube, or a
hot-wire anemometer. Note that your overall system for measuring
intake-air flow must meet the linearity check 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 if 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 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 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 constituent
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 check in Sec. 1065.307 and the
calibration and performance checks in Sec. 1065.330.
(c) Flow conditioning. For any type of raw exhaust flow meter,
condition the flow if 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 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 device.
(2) Do not sample NMHC downstream of the cooling device for
compression-ignition engines, 2-stroke spark-ignition engines, and 4-
stroke spark ignition engines below 19 kW if it causes exhaust
temperatures above 202 [deg]C to decrease to below 180 [deg]C.
(3) Do not sample NOX downstream of the cooling device
if it causes aqueous condensation.
(4) If cooling causes aqueous condensation before the flow reaches
the raw-exhaust flow meter, measure dewpoint and pressure at the flow
meter's inlet. Use this dewpoint for emission calculations in 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 check in Sec. 1065.307 and the
calibration and performance checks 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), 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, critical-flow
venturis, 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 if 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 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
diluted exhaust flow meter. If cooling causes aqueous condensation
before the flow reaches the meter, then measure the dewpoint and
pressure at the flow meter's inlet. Use this dewpoint and pressure for
emission calculations in Sec. 1065.650.
[[Page 54948]]
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 Table 1 of Sec. 1065.205. This
may involve a laminar flow element, an ultrasonic flow meter, a
subsonic venturi, critical-flow venturis, 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 check in Sec. 1065.307
(c) Flow conditioning. For any type of sample flow meter, condition
the flow if 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 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 check 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
performance checks in Sec. 1065.350 and Sec. 1065.355 and, for
continuous measurement, it must also meet the linearity check in Sec.
1065.307.
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 (1), 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 must meet all of the
performance checks for hydrocarbon measurement in subpart D of this
part.
(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 consider 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, RFCH4, 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. Instead
of measuring methane, you may consider that 2% of measured total
hydrocarbons is methane, as described in Sec. 1065.660. 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 performance check 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 dilute a sample with purified air or oxygen
(O2) upstream of the nonmethane cutter to optimize its
performance. You must account for any sample 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.
Instead of measuring methane, you may consider that 2% of measured
total hydrocarbons is methane, as described in Sec. 1065.660. 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.
NOX Measurements
Sec. 1065.270 Chemiluminescent detector.
(a) Application. You may use a chemiluminescent detector (CLD) to
measure NOX concentration in raw or diluted exhaust for
batch or continuous sampling. We generally accept a CLD for
NOX 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 NOX species other than NO and
NO2. Use good engineering judgment to measure other
NOX species, as appropriate. While you may also use other
instruments to measure NOX, as described in Sec. 1065.272
and Sec. 1065.275, 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 check in Sec. 1065.370 and, for
continuous
[[Page 54949]]
measurements, it must also meet the linearity check in Sec. 1065.307.
(c) NO2-to-NO converter. Place upstream of the CLD an
internal or external NO2-to-NO converter that meets the
performance check in Sec. 1065.378. Configure the converter with a
bypass to facilitate this performance check.
(d) Humidity effects. You must generally maintain CLD temperature
to prevent aqueous condensation; however, you may disregard
condensation control if you use one of the following configurations:
(1) The CLD is downstream of an NO2-to-NO converter that
meets the performance check in Sec. 1065.378.
(2) The CLD is downstream of a thermal chiller that meets the
performance check 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 NOX concentration in raw or diluted
exhaust for batch or continuous sampling. We generally accept an NDUV
for NOX measurement, even though it measures only NO and
NO2, since conventional engines and aftertreatment systems
do not emit significant amounts of other NOX species. Use
good engineering judgment to measure other NOX species, as
appropriate.
(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 performance checks in
Sec. 1065.372 and, for continuous measurement, it must also meet the
linearity check in Sec. 1065.307.
(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 performance check in
Sec. 1065.378. Configure the converter with a bypass to facilitate
this performance check.
(d) Humidity effects. You must generally maintain NDUV temperature
to prevent aqueous condensation; however, you may disregard
condensation control if you use one of the following configurations:
(1) The NDUV is downstream of an NO2-to-NO converter
that meets the performance check in Sec. 1065.378.
(2) The NDUV is downstream of a thermal chiller that meets the
performance check in Sec. 1065.376.
Sec. 1065.274 Zirconia (ZrO2) analyzer.
(a) Application. You may use a zirconia (ZrO2) analyzer
to measure NOX concentration in raw exhaust for continuous
sampling, as long as you stay within the analyzer manufacturer's
specified limits with respect to acceptable O2 exhaust
concentrations and exhaust temperature. We generally accept a
ZrO2 analyzer for NOX measurement, even though it
measures only NO and NO2, since conventional engines and
aftertreatment systems do not emit significant amounts of other
NOX species. Use good engineering judgment to measure other
NOX species, as appropriate.
(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 performance checks in Sec. 1065.374 and the linearity check in
Sec. 1065.307.
(c) NO2-to-NO converter. If your ZrO2
analyzer measures only NO, place upstream of the ZrO2
analyzer an NO2-to-NO converter that meets the performance
check in Sec. 1065.378. Configure the converter with a bypass to
facilitate this performance check.
(d) Humidity effects. You must generally maintain ZrO2
analyzer temperature to prevent aqueous condensation; however, you may
disregard condensation control if you use one of the following
configurations:
(1) The ZrO2 analyzer is downstream of an
NO2-to-NO converter that meets the performance check in
Sec. 1065.378.
(2) The ZrO2 analyzer is downstream of a thermal chiller
that meets the performance check in Sec. 1065.376.
O[bdi2]
MEASUREMENTS
Sec. 1065.280 Paramagnetic detection analyzer.
(a) Application. You may use a paramagnetic detection (PMD)
analyzer to measure O2 concentration in raw or diluted
exhaust for batch or continuous sampling. While you may also use a
zirconia analyzer to measure O2, as described in Sec.
1065.283, use a reference procedure based on paramagnetic detection
analyzers for comparison with any proposed alternate measurement
procedures under Sec. 1065.10
(b) Component requirements. We recommend that you use a PMD
analyzer that meets the specifications in Table 1 of Sec. 1065.205.
Note that it must meet the linearity check in Sec. 1065.307 for
continuous measurements.
(c) Interference gas compensation. Compensate for PMD interference
gases according to ISO 8178-1, Section 8.9.4 (incorporated by reference
in Sec. 1065.1010).
Sec. 1065.284 Zirconia (ZrO2) analyzer.
(a) Application. You may use a zirconia (ZrO2) analyzer
to measure O2 concentration in raw exhaust for continuous
sampling.
(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 check in Sec. 1065.307.
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 check in Sec.
1065.307. If the balance uses internal calibration weights for routine
spanning and linearity checks, 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) Periodic verification. Get the balance manufacturer or a
representative approved by the balance manufacturer to verify the
balance performance at least once every 12 months.
(d) Pan design. 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.
(e) 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 check in Sec.
1065.307. If the balance uses an internal calibration process for
routine spanning and linearity checks, the process must be NIST-
traceable.
(c) Periodic verification. Get the balance manufacturer or a
[[Page 54950]]
representative approved by the balance manufacturer to verify the
balance performance at least once every 12 months.
Subpart D--Calibrations and Performance Checks
Sec. 1065.301 Overview and general provisions.
(a) This subpart describes required and recommended calibrations
and performance checks for measurement instruments. See subpart C of
this part for specifications and system requirements that apply to
individual instruments.
(b) You must generally use complete measurement systems when
performing calibrations or performance checks. 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 performance checks, 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 performance check for a
portion of your measurement system, calibrate that portion of your
system and check 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 performance checks. Where we specify the need to use
NIST-traceable standards, you may alternatively ask for our approval to
use international standards that are not traceable to NIST standards.
Sec. 1065.303 Summary of required calibration and performance checks
(a) The following table summarizes the required and recommended
calibrations and performance checks described in this subpart. The
table also indicates when these have to be performed.
Table 1 of Sec. 1065.303--Summary of Required Calibration and
Performance Checks
------------------------------------------------------------------------
Perform calibration or performance
Calibration or performance check check
------------------------------------------------------------------------
Sec. 1065.305: accuracy, Accuracy: not required, but
repeatedly and noise. recommend for initial installation.
Repeatability: not required, but
recommend for initial installation.
Noise: required during initial
installation only if you correct
for noise (See Sec. 1065.658).
Sec. 1065.307: Linearity........ Speed: Initial installation, and
after major maintenance.
Torque: Once every 12 months, and
after major maintenance.
Flows: Once every 12 months, and
after major maintenance unless flow
is verified by propane check or
carbon (or oxygen) balance.
Continuous analyzers: Once every 6
months, and after major
maintenance.
Sec. 1065.308: continuous Initial installation and after major
analyzer system response. system reconfiguration.
Sec. 1065.310: torque........... Initial installation and good
engineering judgment afterward.
Sec. 1065.315: pressure, Initial installation and good
temperature, dewpoint. engineering judgment afterward.
Sec. 1065.320: fuel flow........ Initial installation and good
engineering judgment afterward.
Sec. 1065.325: intake flow...... Initial installation and good
engineering judgment afterward.
Sec. 1065.330: exhaust flow..... Initial installation and good
engineering judgment afterward.
Sec. 1065.340: diluted exhaust Initial installation, after major
flow (CVS). system reconfiguration, and as part
of corrective action.
Sec. 1065.341: CVS and batch After CVS and batch sampler
sampler verification. calibration and in lieu of
linearity check.
Sec. 1065.345: vacuum leak...... Initial installation, within 7 days
of an emission test, and after
major maintenance.
Sec. 1065.350: CO2 NDIR H2O Initial installation and after major
interference. maintenance.
Sec. 1065.355: CO NDIR CO2 and Initial installation and after major
H2O interference. maintenance.
Sec. 1065.360: FID optimization, Calibrate, optimize, and determine
etc. CH4 response: initial installation
and good engineering judgment
afterward.
Check CH4 response: once every 12
months, and after major
maintenance.
Sec. 1065.362: Raw exhaust FID Initial installation and after major
O2 interference. maintenance.
Sec. 1065.365: Nonmethane cutter Once every 6 months, and after major
penetration. maintenance.
Sec. 1065.370: CLD CO2 and H2O Initial installation and after major
quench. maintenance.
Sec. 1065.372: NDUV NMHC and H2O Initial installation and after major
interference. maintenance.
Sec. 1065.374: ZrO2 NH3 Initial installation and after major
interference and NO2 response. maintenance.
Sec. 1065.376: Chiller NO2 Initial installation and after major
penetration. maintenance.
Sec. 1065.378: NO2 to NO Once every 6 months, and after major
converter conversion. maintenance.
Sec. 1065.390: PM balance and Within 12 hours of weighing, and
weighing. after major balance and
maintenance.
------------------------------------------------------------------------
Sec. 1065.305 Performance checks 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 check instrument accuracy or
repeatability, and we require you to check instrument noise only as
specified in paragraph (c) of this section. However, it may be useful
to consider these performance checks 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) If you correct a constituent analyzer for noise as described in
Sec. 65.658, you must have performed the noise performance check in
this section within the past 12 months.
(d) In this section we use the letter ``y'' to denote a generic
measured quantity, the superscript over-bar to denote an arithmetic
mean (i.e.,y<), and the subscript ``ref'' to denote the
reference quantity being measured.
(e) Conduct these checks 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 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 gaseous constituent analyzers,
[[Page 54951]]
use a zero gas that meets the specifications of Sec. 1065.750(a).
(3) Span the instrument 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 gaseous-exhaust constituent analyzers, use a
span gas that meets the specifications of Sec. 1065.750(a).
(4) Use the instrument to quantify a NIST-traceable reference
quantity, yref. Select a reference quantity near the mean
value expected during testing. For all exhaust constituent analyzers,
use a quantity near the flow-weighted average concentration expected at
the standard and known within the specifications of Sec. 1065.750(a).
For a noise performance check, 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 25 values, record the arithmetic mean of the 25 values y
i, and record the standard deviation [sigma]i, of
the 25 values. Refer to Sec. 1065.602 for an example of calculating
arithmetic mean and standard deviation.
(6) Subtract the reference value, yref, from the
arithmetic mean, yi. Record this value as the error,
[egr]i.
(7) Repeat the steps specified in paragraphs (e)(2) through (6) of
this section until you have ten arithmetic means, (y1,
y2, y3, ... y10), ten standard
deviations, ([sigma]1, [sigma]2,
[sigma]3, ... [sigma]10), and ten errors
([egr]1, [egr]2, [egr]3, ...
[egr]10).
(8) Instrument accuracy is the absolute difference between the
reference quantity, yref and the arithmetic mean of the ten
yi. Refer to the accuracy example calculation in Sec.
1065.602. We recommend that instrument accuracy be within the
specifications in Table 1 of Sec. 1065.205.
(9) Repeatability is two times the standard deviation of the ten
errors: (e.g. repeatability = 2 [middot]
[sigma][egr]). Refer to the
standard deviation example calculation in Sec. 1065.602. We recommend
that instrument repeatability be within the specifications in Table 1
of Sec. 1065.205.
(10) Noise is two times the root mean square of the ten standard
deviations, (e.g. noise = 2 [middot]
rms[sigma]). Refer to the root
mean square example 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.
(11) 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 all the following criteria:
(i) You try to correct the problem.
(ii) Your measurement systems meet all required calibration,
performance checks, and validation specifications.
(iii) The measurement deficiency does not affect your ability to
show that your engines comply with all applicable emission standards.
Sec. 1065.307 Linearity check.
(a) Perform a linearity check on each measurement system listed in
Table 1 of this section at least as frequently as indicated in the
table, or more frequently, consistent with good engineering judgment;
for example, if the measurement system manufacturer recommends it. Note
that this linearity check replaces requirements that we previously
referred to as calibration specifications.
(b) If a measurement system does not meet the applicable linearity
criteria, 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 get us to approve it
under Sec. 1065.10.
(c) The intent of a linearity check is to determine that a
measurement system responds proportionally over the measurement range
of interest. A linearity check generally consists of introducing a
series of at least 10 reference values to a measurement system. These
reference values are about evenly spaced from the lowest to the highest
values expected during emission testing. The measurement system
quantifies each reference value. The measured values are then
collectively compared to the reference values by using the linearity
criteria specified in Table 1 of this section.
(d) Use the following linearity-check protocol, or use good
engineering judgment to develop a different protocol that satisfies the
intent of this section, as described in paragraph (c) of this section:
(1) In this paragraph (d), we use the letter ``y'' to denote a
generic measured quantity, the superscript over-bar to denote an
arithmetic mean (i.e., 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 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 gaseous constituent analyzers, use a zero gas
that meets the specifications of Sec. 1065.750(a).
(4) Span the instrument 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 gaseous-exhaust constituent analyzers, use a
span gas that meets the specifications of Sec. 1065.750(a).
(5) Select 10 reference values, yrefi that are nominally
evenly spaced from the lowest to the highest values expected during
emission testing. Generate reference quantities as described in
paragraph (e) of this section. For gaseous-exhaust constituent
analyzers, use gas concentrations known to be within the specifications
of Sec. 1065.750(a).
(6) Select the greatest reference value and introduce it to the
measurement system.
(7) 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.
(8) At a frequency of f Hz specified in Table 1 of Sec. 1065.205,
measure the reference value 25 times and record the arithmetic mean of
the 25 values, yi. Refer to Sec. 1065.602 for an example of
calculating an arithmetic mean.
(9) Select smallest reference value, and repeat steps in paragraphs
(d)(7) and (d)(8) of this section.
(10) Alternate between selecting the highest and lowest remaining
untested reference values until you have measured all the reference
values.
(11) Use the arithmetic means, yi, and reference values,
yrefi, to calculate statistical values to compare to the
criteria specified in Table 1 of this section. Use the statistical
calculations as described in Sec. 1065.602.
(e) This paragraph (e) describes recommended methods for generating
reference values for the linearity-check protocol in paragraph (d) 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 traceable to NIST standards. Use the
following recommended methods to generate reference values or use good
engineering judgment to select a different method:
[[Page 54952]]
(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, Alternately, you may
use the engine or dynamometer itself to generate a nominal torque that
is measured by a reference load cell 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 check in this
section.
(3) Fuel rate. Operate the engine at a series of constant fuel-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 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.
(4) 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 or diverter valve or a
variable speed blower or pump to control the range of flow rates. Use
the reference meter's response as the reference values. 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. Ensure that your reference meter
is calibrated by the flow meter manufacturer and that its calibration
is traceable to NIST. If you use the difference of two flow
measurements to determine a single flow rate, you may use one of the
measurements as a reference for the other.
(5) Gas division. At the outlet of the gas division system, connect
a gas analyzer that meets the linearity check described in this
section. Operate this analyzer consistent with how you would operate it
for emission testing. Connect to the gas divider inlet a span gas for
the analyzer. 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 quotient of
the analyzer response divided by the span gas concentration as the
reference value.
(6) 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.
BILLING CODE 6560-50-P
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[GRAPHIC]
[TIFF OMITTED]
TP10SE04.180
BILLING CODE 6560-50-C
Sec. 1065.308 Continuous gas analyzer system response check.
(a) Scope and frequency. Perform this check after installing or
replacing a gas analyzer that you use for continuous sampling. Also
perform this check if you reconfigure your system in a way that would
change system response. For example, you add a significant volume to
the transfer lines by increasing their length or adding a filter. As
another example, you change the frequency at which you sample and
record gas analyzer concentrations.
(b) Measurement principles. This check is an overall system
response check for continuous analyzers. It evaluates two aspects of
instrument response, as follows:
(1) Uniform response. To determine a single gas concentration, you
may combine more than one gas
[[Page 54954]]
measurement. For example, you may measure an interference gas and use
its value in an algorithm to compensate the value of another measured
gas concentration. The response of the interference gas instrument must
match the response of the instrument that it is compensating.
(2) Overall system response. The overall system response and the
system's recording frequency must be properly matched. Gas analyzer
systems must be optimized such that their overall response to a rapid
change in concentration is recorded at an appropriate frequency to
prevent loss of information.
(c) System requirements. The response check is evaluated by two
performance criteria, as follows:
(1) Compensated signals must have a uniform rise and fall during
the full response to a step change. During a system response to a rapid
change in multiple gas concentrations, the shape of any compensated
signal must have no more than one inflection point. In other words, the
second derivative of any compensated signal must change sign from
negative (-) to positive (+) no more than once whenever a multi-
component step increase occurs, and the second derivative must change
sign from positive (+) to negative (-) no more than once whenever a
multi-component step decrease occurs
(2) The product of the mean rise time and the sampling frequency
must be at least 5, and the product of the mean fall time and the
sampling frequency must be at least 5.
(d) Procedure. Use the following procedure to check the response of
your continuous gas analyzer system.
(1) Instrument setup. Follow the analyzer system manufacturers'
start-up and operation instructions. Adjust the system as needed to
optimize performance.
(2) Equipment setup. Connect a zero air source to one inlet of a
fast acting 3-way valve (2 inlets, 1 outlet). Connect an NO, CO,
CO2, C3H8 quad-blend span gas to the
other valve inlet. Connect the valve outlet to a heated line at 50
[deg]C, and 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 gas analyzer system's probe or to the overflow fitting
between the probe and transfer line.
(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 you would 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.
(4) Performance evaluation.
(i) Uniform response. Compute the second derivative for any
compensated analyzer signals. The second derivative must change sign
from negative (-) to positive (+) no more than once whenever span gas
was flowed, and the second derivative must change sign from positive
(+) to negative (-) no more than once whenever zero gas was flowed. If
it did, determine if the cause was an interference gas compensation
signal. If you can positively demonstrate that any failure was not
caused by an interference compensation signal, then the analyzer system
passes this test. Otherwise, adjust the compensation algorithms' time-
alignment and/or dispersion to result in a uniform rise and fall during
this performance check.
(ii) Rise time, fall time, and recording frequency. Calculate the
mean rise time, T10-90 and mean fall time T90-10
for each of the analyzers. Multiply these times (in s) by their
respective recording frequencies in Hertz (1/s). 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/or fall time. You may not use
interpolation to increase the number or recorded values. In other
words, each recorded value must be a unique record of the actual
analyzer signal.
Measurement of Engine Parameters and Ambient Conditions
Sec. 1065.310 Torque calibration.
Calibrate your torque measurement system upon initial installation,
and use good engineering judgment to re-calibrate your system.
Calibrate torque with the lever-arm dead-weight technique or the
transfer technique, as described in paragraphs (a) and (b) of this
section. We define the NIST ``true value'' torque as the torque
calculated by taking the product of a weight or force traceable to NIST
and a sufficiently accurate horizontal distance along a lever arm,
corrected for the lever arm's hanging torque.
(a) The lever-arm dead-weight technique involves placing known
weights at a known horizontal distance from the torque-measuring
device's center of rotation. You need two types of equipment:
(1) Calibration weights or force. This technique requires
calibration weights or a force apparatus traceable to NIST standards.
Use at least six calibration points for each applicable torque-
measuring range, spacing the points about equally over the range.
(i) For calibration weights, determine their force by multiplying
their NIST-traceable masses by your local acceleration of Earth's
gravity. The local acceleration of gravity, ag at your
latitude, longitude, and elevation may be determined by entering your
position and elevation data into the United States' National
Oceanographic and Atmospheric Administration's surface gravity
prediction Web site: http://www.ngs.noaa.gov/cgi-bin/
grav_pdx.prl. 
If this Web site is unavailable,
you may use the equations in Sec. 1065.630, which return your
local acceleration of gravity based on your latitude and elevation.
Make sure the lever arms are perpendicular to gravity.
(ii) [Reserved]
(2) Lever arm. Apply the calibration weights or force apparatus to
the torque-sensing device through a lever arm. The length of the lever
arm, from the point where the calibration force or weights are applied
to the dynamometer centerline, must be known accurately enough to allow
the system to meet the linearity criteria in Table 1 of Sec. 1065.307.
Take into account the torque-producing effect of the lever arm's mass.
You may balance the lever arm's mass to minimize the torque-producing
effect.
(b) The transfer technique involves calibrating a master load cell,
such as a dynamometer-case load cell. You may calibrate the master load
cell with known calibration weights or force at known horizontal
distances. Alternatively, you may use a pre-calibrated master load cell
to transfer this calibration to the device that measures engine torque.
The transfer technique involves the following three main steps:
(1) Pre-calibrate a master load cell using weights or force and a
lever arm as specified in paragraph (a) of this section. Run or vibrate
the dynamometer during this calibration to reduce frictional static
hysteresis.
(2) The measured horizontal distance from the dynamometer
centerline to the point where you apply a weight or force must be
accurate to within ±0.5 %. Balance the arms or know their
net hanging torque to within ±0.5 %.
(3) Transfer calibration from the case or master load cell to the
torque-
[[Page 54955]]
measuring device with the dynamometer operating at a constant speed.
Calibrate the torque-measurement device's readout to the master load
cell's torque readout at a minimum of six loads spaced about equally
across the full useful ranges of both measurement devices. Transfer the
calibration so it meets the linearity criteria in Table 1 of Sec.
1065.307.
Sec. 1065.315 Pressure, temperature, and dewpoint calibration.
(a) Follow the measurement-system manufacturer's instructions and
recommended frequency for calibrating pressure, temperature, and
dewpoint, upon initial installation and use good engineering judgment
to re-calibrate, as follows:
(1) Pressure. We recommend temperature-compensated, digital-
pneumatic, or deadweight pressure calibrators, with data-logging
capabilities to minimize transcription errors.
(2) Temperature. We recommend digital dry-block or stirred-liquid
temperature calibrators, with datalogging capabilities to minimize
transcription errors.
(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.
(b) You may remove system components for off-site calibration.
Flow-Related Measurements
Sec. 1065.320 Fuel flow calibration.
(a) Follow the measurement-system manufacturer's instructions for
calibrating a fuel flow meter upon initial installation and use good
engineering judgment to re-calibrate. We recommend using a scale and a
stopwatch.
(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 your tubing configuration upstream and
downstream of your flow meter.
Sec. 1065.325 Intake flow calibration.
(a) Follow the measurement-system manufacturer's instructions for
calibrating intake-air flow upon initial installation, and use good
engineering judgment to re-calibrate. We recommend using a calibration
subsonic venturi.
(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 your tubing configuration upstream and
downstream of your flow meter.
(c) If you use a subsonic venturi for intake flow measurement, we
recommend that you calibrate it as described in Sec. 1065.340.
Sec. 1065.330 Exhaust flow calibration.
(a) Follow the measurement-system manufacturer's instructions for
calibrating exhaust flow upon initial installation, and use good
engineering judgment to re-calibrate. We recommend that you use a
calibration subsonic venturi and simulate exhaust temperatures by
incorporating a heat exchanger between the calibration meter and your
exhaust-flow meter.
(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 your tubing configuration upstream and
downstream of your flow meter.
(c) If you use a subsonic venturi for intake 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 check in Sec. 1065.341.
(c) Reference flow meter. Calibrate a CVS flow meter using a
reference subsonic venturi flow meter. Long radius ASME/NIST flow
nozzles are acceptable. Use a reference flow meter that is within
±1 % NIST traceability. 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 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. Calibrate a PDP flow
meter as follows:
(1) Connect the system as shown in Figure 1 of this section.
(2) Eliminate leaks between the calibration flow meter and the PDP
such that total leakage is less than 0.3 % of the lowest 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 average absolute inlet
temperature, Tin.
(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 CFV and record the mean of at least 25
measurements of each of the following quantities:
(i) Flow rate of the reference flow meter, n.
(ii) Temperature at the PDP inlet, Tin.
(iii) Static absolute pressure at the PDP inlet, Pin.
(iv) Static absolute pressure at the PDP outlet, Pout.
(v) PDP speed, fPDP.
(7) Incrementally close the restrictor valve to decrease the
absolute pressure at the inlet to the PDP, Pin.
(8) Repeat the steps in paragraphs (e)(6) and(e)(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 (e)(9) of this
section for each speed that 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 check (i.e.,
propane check) as described in Sec. 1065.341
(13) Use the flow equation to determine PDP flow during emission
testing. Do not use the PDP below the lowest inlet pressure tested
during calibration.
(f) CFV calibration. Calibrate a CFV to verify its discharge
coefficient, Cd and the lowest inlet pressure at which you
may use your CFV. Calibrate a CFV flow meter as follows:
(1) Connect the system as shown in Figure 1 of this section.
(2) Eliminate leaks between the calibration flow meter and the CFV
such
[[Page 54956]]
that total leakage is less than 0.3 % of total flow at the highest
restriction.
(3) While the CFV operates, maintain a constant temperature at the
CFV inlet within ±2 % of the average absolute inlet
temperature, Tin.
(4) Start the blower downstream of the CFV.
(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 of at least 25
measurements of each of the following quantities:
(i) Flow rate of the reference flow meter, n.
(ii) Optionally, dewpoint of the calibration air, Tdew.
See Sec. 1065.640 for permissible assumptions.
(iii) Temperature at the venturi inlet, Tin.
(iv) Static absolute pressure at the venturi inlet, Pin.
(7) Incrementally close the restrictor valve to decrease the
absolute pressure at the inlet to the CFV, Pin.
(8) Repeat the steps in paragraphs (f)(6) and (f)(7) of this
section to record data at a minimum of ten restrictor positions, such
that you test the full range of inlet pressures expected during
testing.
(9) Determine Cd and the lowest inlet pressure at which
you may use your CFV as described in Sec. 1065.640.
(10) Verify the calibration by performing a CVS check (i.e.,
propane check) as described in Sec. 1065.341.
(11) Use the Cd to determine CFV flow during an emission test. Do
not use the CFV below the lowest inlet pressure tested during
calibration.
(g) SSV calibration. Calibrate an SSV flow meter as follows:
Calibrate an SSV to determine its calibration coefficient, Cd for the
range of inlet pressures over which you may use your SSV. Calibrate an
SSV flow meter as follows:
(1) Connect the system as shown in Figure 1 of this section.
(2) Eliminate leaks between the calibration flow meter and the SSV
such that total leakage is less than 0.3 % of total flow at the highest
restriction.
(3) While the SSV operates, maintain a constant temperature at the
SSV inlet within ±2 % of the average absolute inlet
temperature, Tin.
(4) Start the blower downstream of the SSV.
(5) Set the variable restrictor or variable-speed blower to a flow
rate greater than the greatest flow rate expected during testing.
Because we do not allow extrapolation of flow rates beyond calibrated
values, we recommend that you ensure that the SSV throat Reynolds
number (Re#) at your 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 25
measurements of each of the following quantities:
(i) Flow rate of the reference flow meter, n.
(ii) Optionally, dewpoint of the calibration air, Tdew.
See Sec. 1065.640 for permissible assumptions.
(iii) Temperature at the venturi inlet, Tin.
(iv) Static absolute pressure at the venturi inlet, Pin.
(v) Static absolute pressure at the venturi throat, Pth.
(7) Incrementally close the restrictor valve or decrease the blower
speed to decrease the flow rate.
(8) Repeat the steps in paragraphs (g)(6) through (g)(7) of this
section to record data at a minimum of ten flow rates.
(9) Determine a functional form of Cd versus Re# by using the
collected data and the equations in Sec. 1065.640.
(10) Verify the calibration by performing a CVS check (i.e.,
propane check) as described in Sec. 1065.341 using the new Cd 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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[GRAPHIC]
[TIFF OMITTED]
TP10SE04.008
BILLING CODE 6560-50-C
Sec. 1065.341 CVS and batch sampler verification (i.e. propane
check).
(a) Perform this check to determine if there is a discrepancy in
your measured values of diluted exhaust flow. You may also perform this
check to determine if there is a discrepancy in a batch sampling system
that extracts a sample from a CVS. Failure of this check might indicate
that one or more of the following problems might require corrective
action:
(1) Incorrect analyzer calibration. Re-calibrate FID analyzer or
repair or replace analyzer.
(2) Leaks. Inspect CVS tunnel, connections, and fasteners and
repair or replace components.
(3) Poor mixing. Perform the check as described in paragraph (b) of
this section while traversing sampling probe across diameter of tunnel,
vertically and horizontally. If analyzer response indicates a deviation
that exceeds ±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.
(4) Hydrocarbon contamination in the sample system. Perform the
hydrocarbon contamination check as described in Sec. 1065.520.
(5) Change in CVS calibration. Perform an in-situ calibration of
the
[[Page 54958]]
CVS flow meter as described in Sec. 1065.340.
(6) Other problems with the CVS or sampling check hardware or
software. Inspect CVS system, the CVS check hardware, and your software
for discrepancies.
(b) C3H8 check. This 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,
you might have to account for the non-ideal gas behavior of
C3H8 in your reference flow meter. You inject the
reference C3H8 into the CVS and then calculate
the mass you injected using your NMHC measurements and CVS flow rate
measurements.
(c) Prepare for this check as follows:
(1) Obtain a cylinder charged with C3H8.
Determine the reference cylinder's full weight within ±0.5%
if you use a reference mass instead of a reference flow rate.
(2) Select appropriate flow rates for the CVS and
C3H8.
(3) Select a C3H8 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 any heat exchangers in the sampling system.
(6) Allow heated components such as sample lines, filters, and
pumps to stabilize at operating temperature.
(7) You may purge your NMHC sampling system during stabilization.
(8) If applicable, perform a vacuum side leak check of the NMHC
sampling system as described in Sec. 1065.345.
(9) You may also conduct any other calibrations or performance
checks on any equipment or analyzers.
(d) Zero, span, and check for contamination of the NMHC sampling
system, as follows:
(1) Select the lowest NMHC analyzer range that can measure the
C3H8 concentration expected for your CVS and
C3H8 flow rates.
(2) Zero the NMHC analyzer using zero air introduced at the
analyzer port.
(3) Span the NMHC analyzer using C3H8 span
gas introduced at the analyzer port.
(4) Overflow zero air at the NMHC probe or into a fitting between
the NMHC probe and the transfer line.
(5) Measure the stable NMHC concentration of the NMHC sampling
system as overflow zero air flows.
(6) If the overflow NMHC concentration exceeds 2% of the expected
C3H8 concentration, determine the source of the
contamination and take corrective action, such as cleaning the system
or replacing contaminated portions. Do not proceed until contamination
is eliminated.
(7) If the overflow NMHC concentration does not exceed 2% of the
expected C3H8 concentration, record this value as
xNMHCpre and use it to correct for NMHC contamination as
described in Sec. 1065.660.
(e) Perform the propane check as follows:
(1) For batch NMHC sampling, connect clean storage media, such as
evacuated bags.
(2) Operate NMHC measurement instruments according to the
instrument manufacturer's instructions.
(3) If you choose to correct for dilution air background
concentrations of NMHC, measure and record background NMHC.
(4) Zero any integrating devices.
(5) Begin sampling, and start any flow integrators.
(6) Release the contents of the propane reference cylinder and the
rate you selected. If you use a reference flow rate
C3H8, start integrating this flow rate.
(7) Continue to release the cylinder's contents for a duration of
time that is at least as long as your shortest test interval for
emission testing.
(8) Shut off the C3H8 reference cylinder and
continue sampling until you have accounted for time delays due to
sample transport delays and analyzer response times.
(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 NMHC correct for drift, contamination, and
background.
(3) Calculate total C3H8 mass based on your
CVS and NMHC data as described in Sec. 1065.650 and Sec. 1065.660
using of the molar mass of C3H8,
MC3H8 instead the molar mass of NMHC,
MNMHC.
(4) If you use a reference mass, determine the cylinder's post-test
weight within ±0.5%, and determine the
C3H8 reference mass by subtracting empty cylinder
weight from the full cylinder weight.
(5) Subtract the reference C3H8 mass from
your calculated mass. If this difference is within ±2% of
the reference mass, the CVS passes this check. If not, take corrective
action as described in paragraph (a) of this section.
(g) Batch sampler check. You may repeat the
C3H8 check to check a batch sampler, such as a PM
secondary dilution system.
(1) Configure your NMHC sampling system to extract a sample near
the location of your batch sampler's storage media (e.g., PM filter).
If the absolute pressure at this location is too low to extract an NMHC
sample, you may sample NMHC from the batch sampler pump's exhaust. Use
caution when sampling from pump exhaust because an acceptable pump leak
downstream of a batch sampler flow meter will cause a false failure of
the C3H8 check.
(2) Repeat the C3H8 check described in this
section, sampling NMHC from your batch sampler.
(3) Calculate C3H8 mass taking into account
any secondary dilution from your batch sampler.
(4) Subtract the reference C3H8 mass from
your calculated mass. If this difference is within ±5% of
the reference mass, the batch sampler passes this check. If not, take
corrective action as described in paragraph (a) of this section.
Sec. 1065.345 Vacuum-side leak check.
Within seven days before each test, check for vacuum-side leaks as
described in this section. Check for vacuum-side leaks using one of the
following two procedures:
(a) Perform a flow-rate leak-test as follows:
(1) For a given sampling system, 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 each analyzer pump. After stabilizing the system,
verify that the flow through each analyzer is less than 0.5% of the in-
use flow rate. You may use nominal analyzer and bypass flows to
estimate in-use flow.
(b) Perform an over-flow leak-test as follows:
(1) For a given sampling system, 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 and route to the end of the
transfer line.
(iii) A three-way valve installed in-line between a probe and
transfer line.
(2) After stabilizing the system, verify that the measured span gas
concentration is within the measurement accuracy and repeatability of
the analyzer. Note that a measured value lower than expected may be an
indication of a leak, but a higher than expected concentration may be
an indication of a problem with the span gas or the analyzer itself. A
higher than expected concentration does not indicate a leak.
[[Page 54959]]
CO AND CO2 MEASUREMENTS
Sec. 1065.350 H2O interference check for CO2
NDIR analyzers.
(a) Scope and frequency. If you measure CO2 using an
NDIR analyzer, check for H2O interference after initial
analyzer installation and after any major maintenance.
(b) Measurement principles. H2O can interfere with an
NDIR analyzer's response for CO2. If your NDIR analyzer uses
compensation algorithms that utilize measurements of other gases to
meet this interference check, simultaneously conduct such measurements
to test the algorithms during the analyzer interference check.
(c) System requirements. A CO2 NDIR analyzer must have
an H2O interference that is less than 2% of the lowest flow-
weighted average CO2 concentration expected during testing,
though we strongly recommend a lower interference of less than 1%.
(d) Procedure. Perform the interference check as follows:
(1) Start, operate, zero, and span the CO2 NDIR analyzer
according to the instrument manufacturer's instructions.
(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) Upstream of any sample dryer used during testing, introduce the
water-saturated test gas.
(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 60 s at a nominal frequency of 5 Hz to record 300 data
points. Calculate the arithmetic mean of these 300 points.
(e) If the arithmetic mean of the 300 points is less than 2% of the
flow-weighted average concentration of CO2 expected at the
standard, then the analyzer meets the interference check.
(f) You may use a CO2 NDIR analyzer that you determine
does not meet this performance check, as long as you meet all the
following criteria:
(1) You try to correct the problem.
(2) The measurement deficiency does not affect your ability to show
that your engines comply with all applicable emission standards.
Sec. 1065.355 H2O and CO2 interference check
for CO NDIR analyzers.
(a) Scope and frequency. If you measure CO using an NDIR analyzer,
check for H2O and CO2 interference after initial
analyzer installation and after any major maintenance.
(b) Measurement principles. H2O and CO2 can
positively interfere with an NDIR analyzer by causing a response
similar to CO. If your NDIR analyzer uses compensation algorithms that
utilize measurements of other gases to meet this interference check,
simultaneously conduct such measurements to test the algorithms during
the analyzer interference check.
(c) System requirements. A CO NDIR analyzer must have combined
H2O and CO2 interference that is less than 2% of
the flow-weighted average concentration of CO expected at the standard,
as measured in paragraph (d) of this section, though we strongly
recommend a lower interference of less than 1%.
(d) Procedure. Perform the interference check as follows:
(1) Start, operate, zero, and span the CO NDIR analyzer according
to the instrument manufacturer's instructions.
(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) Upstream of any sample dryer used during testing, introduce the
water-saturated CO2 test gas.
(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 at its nominal frequency to record 300 data points.
Calculate the arithmetic mean of these 300 points.
(6) Multiply this mean by the ratio of expected CO2 to
span gas CO2 concentration. In other words, estimate the
flow-weighted average dry concentration of CO2 expected
during testing, and then divide this value by the concentration of
CO2 in the span gas used for this check. Then multiply this
ratio by the mean of the 300 values recorded during this check.
(e) If the result of (6) is less than 2% of the flow-weighted
average concentration of CO expected at the standard, then the analyzer
meets the interference check.
(f) You may use a CO NDIR analyzer that does not meet this
performance check as long as you meet all the following criteria:
(1) You try to correct the problem.
(2) The measurement deficiency does not affect your ability to show
that your engines comply with all applicable emission standards.
HYDROCARBON MEASUREMENTS
Sec. 1065.360 FID optimization and performance checks.
(a) Scope and frequency. For all FID analyzers, perform the
following:
(1) Calibrate a FID upon initial installation and according to good
engineering judgment, as described in paragraph (b) of this section.
Calibrate on a carbon number basis of one (1), C1.
(2) Optimize, a FID's response to various hydrocarbons after
initial analyzer installation and after any major maintenance, as
described in paragraph (c) of this section.
(3) Determine a FID's CH4 response factor after initial
analyzer installation and after any major maintenance as described in
paragraph (d) of this section.
(4) Check CH4 response once every 12 months.
(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 a C3H8, balance
synthetic air, calibration gas that meets the specifications of Sec.
1065.750. Calibrate 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.
(c) FID Response optimization. Use good engineering judgement for
initial instrument start-up and basic operating adjustment using FID
fuel and zero air. Heated FIDs must be at their specified operating
temperature. Optimize FID response at the operating range expected to
be used during emission testing. Optimization involves adjusting flows
and pressures to minimize response variations to different hydrocarbon
species that are expected to be in the exhaust. Use good engineering
judgment to trade off peak FID response to propane-in-air to achieve
minimal response variations to different hydrocarbons. A good example
of trading off response to propane for relative responses to other
hydrocarbon species is given in Society of Automotive Engineers (SAE)
Paper No. 770141, ``Optimization of Flame Ionization Detector for
Determination of Hydrocarbon in Diluted Automotive Exhausts;'' author
Glenn D. Reschke (incorporated by reference in Sec. 1065.1010). After
the optimum flow rates have been determined, record them for future
reference.
[[Page 54960]]
(d) CH4 response factor determination. Since FID analyzers
generally do not have a 1.00 CH4 response factor, determine
each FID analyzer's CH4 response factor after FID
optimization. Because we do not limit the range of FID analyzer's
RFCH4, you must use the most recent RFCH4 that you measured according
to this section. Use the most recent RFCH4 in the calculations for NMHC
determination as described in Sec. 1065.660. These calculations
compensate for CH4 response. Determine a FID analyzer's
response CH4 factor as follows:
(1) Select a propane (C3H8) calibration gas
that meets the specifications of Sec. 1065.750 and has a concentration
typical of the flow-weighted average concentration expected at the
hydrocarbon standard. Record the calibration concentration of the gas.
(2) Select a methane (CH4) calibration gas that meets
the specifications of Sec. 1065.750 and has a concentration typical of
the flow-weighted average concentration expected at the hydrocarbon
standard. Record the calibration 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
(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.
(5) Zero the FID with zero air that meets the specifications of
Sec. 1065.750.
(6) Span the FID with the calibration gas that you selected in
paragraph (d)(1) of this section.
(7) Introduce at the inlet of the FID analyzer the CH4
calibration gas that you selected in 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 its output for 60 s at a nominal frequency of 5 Hz to record 300
data points. Calculate the arithmetic mean of these 300 points.
(10) Divide the mean measured concentration by the recorded
calibration concentration of the CH4 calibration gas. The
result is the FID analyzer's response factor for CH4, RFCH4.
(e) FID CH4 response check. Check the FID CH4 response by
performing the following:
(1) Perform the CH4 response factor determination as
described in paragraph (d) of this section.
(2) If the CH4 response factor is within ±5%
of its most recently determined value, the FID passes the FID flow
check.
(3) If the FID does not pass this check, first verify that the
pressures and flow rates of FID fuel, burner air, and sample are each
within ±0.5% of their most recently recorded values. These
values are recorded each time you conduct a FID response optimization
as described in paragraph (c) of this section. You may adjust these
flows as necessary.
(4) Repeat the CH4 response factor determination as
described in paragraph (d) of this section.
(5) If the pressures and/or flows are correct, but the
CH4 response factor is not within ±5% of its most
recently determined value, then repeat the FID response optimization as
described in paragraph (c) of this section.
(6) Repeat the CH4 response factor as described in
paragraph (d) of this section.
(7) Use this CH4 response factor, RFCH4, in the
calculations for NMHC determination as described in Sec. 1065.660.
Sec. 1065.362 Raw exhaust FID O2 interference check.
(a) Scope and frequency. If you use a FID analyzer for raw exhaust
measurements, perform an O2 interference check 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 check.
(c) System requirements. Your FID must meet the O2
interference check according to ISO 8178-1, Section 8.8.3 (incorporated
by reference in Sec. 1065.1002).
Sec. 1065.365 Nonmethane cutter penetration fractions determination.
(a) Scope and frequency. If you use a FID analyzer and a nonmethane
cutter to measure methane (CH4), determine the nonmethane
cutter's penetration fractions of CH4, PFCH4 and ethane,
PFC2H6 as described in this section. Perform this check after
installing the nonmethane cutter, and within six months after the
previous check. This check must be repeated within six months of the
check to verify that the catalytic activity of the cutter has not
deteriorated.
(b) Measurement principles. A nonmethane cutter removes nonmethane
hydrocarbons from the exhaust stream before the FID analyzer measures
hydrocarbon concentrations. An ideal nonmethane cutter would have PFCH4
of 1.000, and the penetration fraction for all other hydrocarbons would
be 0.000, as represented by PFC2H6. The emission calculations in Sec.
1065.660 use the actual measured values of PFCH4 and PFC2H6 to account
for less than ideal nonmethane cutter performance.
(c) System requirements. We do not limit penetration fractions to a
certain range. However, we do recommend that you optimize a nonmethane
cutter by adjusting its catalyst temperature to achieve PFCH4 >0.9 and
PFC2H6 < 0.1 as determined by paragraph (d) of this section. If we use a
nonmethane cutter for testing, it will meet this recommendation. If
adjusting catalyst temperature does not result in achieving both of
these specifications simultaneously, we recommend that you replace the
catalyst. Use the most recently determined penetration values from this
section to calculate the concentration of NMHC, xNMHC as described in
Sec. 1065.660.
(d) Procedure. Determine penetration fractions as follows:
(1) Select CH4 and C2H6 analytical
gas mixtures that meet the specifications of Sec. 1065.750 with
concentrations typical of the flow-weighted average concentrations
expected at the hydrocarbon standard.
(2) Start and operate the nonmethane cutter according to the
manufacturer's instructions.
(3) Confirm that the FID analyzer meets all of the specifications
of Sec. 1065.360.
(4) Start and operate the FID analyzer according to the
manufacturer's instructions.
(5) Connect the FID analyzer to the outlet of the nonmethane
cutter.
(6) Introduce the CH4 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 its response.
(8) While the analyzer measures the sample's concentration, record
its output for 60 s at a nominal frequency of 5 Hz to record 300 data
points. Calculate the arithmetic mean of these 300 points.
(9) Reroute the flow path to bypass the nonmethane cutter and
repeat the steps in paragraphs (d)(6) through (d)(8) of this section.
(10) Divide the mean concentration measured through the nonmethane
cutter by the mean concentration measured after bypassing the
[[Page 54961]]
nonmethane cutter. The result is the CH4 penetration
fraction (PFCH4)
(11) Repeat steps in paragraphs (b)(6) through (b)(10) of this
section but with the C2H6 analytical gas mixture
instead of the CH4 analytical gas mixture. The result is the
C2H6 penetration fraction (PFC2H6).
NOX MEASUREMENTS
Sec. 1065.370 CLD CO2 and H2O quench check.
(a) Scope and frequency. If you use a CLD analyzer to measure
NOX, check for H2O and CO2 quench
after installing the CLD analyzer and after performing major
maintenance.
(b) Measurement principles. H2O and CO2 can
negatively interfere with a CLD's NOX response by
collisional quenching, which inhibits the chemiluminescent reaction
that a CLD utilizes to detect NOX. The calculations in Sec.
1065.672 that are used to determine 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 your 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 less than ±2%,
though we strongly recommend a quench of ± 1%. Combined
quench is the sum of the CO2 quench determined as described
in paragraph (d) of this section, plus the H2O quench
determined as described in paragraph (e) of this section.
(d) CO2 quench-check 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 has a concentration that is approximately twice the
maximum CO2 concentration expected 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,
(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 to ensure correct gas divider
operation.
(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, xCO2 and use it in the quench check
calculations in Sec. 1065.672.
(8) Measure the NO concentration downstream of the gas divider. If
your CLD has an operating mode in which it detects only NO, as opposed
to total NOX, operate the CLD in that operating mode. Record
this concentration, xNO+CO2, and use it in the quench check
calculations in Sec. 1065.672.
(9) Switch the three-way valve so that 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, xNO+N2, and use it in the quench check
calculations in Sec. 1065.672.
(11) Calculate CO2 quench as described in Sec.
1065.672.
(e) H2O quench check procedure.
(1) For a CLD analyzer equipped with a sample dryer, as described
in Sec. 1065.145(d)(2)), you may assume an H2O quench value
of 0% if you can show that the dryer maintains less than 4 [deg]C
dewpoint at its outlet when it receives at its inlet the maximum
dewpoint expected during testing. Determine dewpoint as described in
Sec. 1065.145(d)(2)).
(2) For a CLD analyzer without a dryer, take the following steps to
determine H2O quench:
(i) If your CLD has an operating mode in which it detects only NO,
as opposed to total NOX, operate the CLD in that operating
mode.
(ii) Measure an NO calibration span gas that meets the
specifications of Sec. 1065.750 and is near the maximum concentration
expected at the standard. Record this concentration, xNOdry.
(iii) Bubble the same NO gas through distilled water in a sealed
vessel at (25 ±10) [deg]C. Record the vessel water
temperature, Tsat and pressure, Psat. To prevent
subsequent condensation, make sure the humidified sample will not be
exposed to temperatures lower than Tsat during transport from the
sealed vessel's outlet to the CLD. We recommend heated transfer lines.
(iv) Use the CLD to measure the NO concentration of the humidified
span gas and record this value, xNOwet.
(v) Use the recorded values from this paragraph (e) to calculate
the H2O quench as described in Sec. 1065.672.
(f) If the sum of the H2O quench plus the CO2
quench is not less than 2%, take corrective action by repairing or
replacing the analyzer. Before using a CLD for emission testing,
demonstrate that the corrective action resulted in less than 2%
combined quench.
Sec. 1065.372 NDUV analyzer NMHC and H2O interference
check.
(a) Scope and frequency. If you measure NOX using an
NDUV analyzer, check for H2O and hydrocarbon interference
after initial analyzer installation and after any major maintenance.
(b) Measurement principles. Hydrocarbons and H2O can
positively interfere with an NDUV analyzer by causing a response
similar to NOX. If your NDUV analyzer uses compensation
algorithms that utilize measurements of other gases to meet this
interference check, simultaneously conduct such measurements to test
the algorithms during the analyzer interference check.
(c) System requirements. A NOX NDUV analyzer must have
combined H2O and hydrocarbon interference that is less than
±2% of the flow-weighted average concentration of
NOX expected at the standard, as measured in paragraph (d)
of this section, though we strongly recommend a lower interference of
less than ±1%.
(d) Procedure. Perform the interference check as follows:
(1) Start, operate, zero, and span the NOX NDUV analyzer
according to the instrument manufacturer's instructions.
(2) We recommend that you extract engine exhaust to perform this
check. Use a CLD that meets the specifications of subpart C of this
part to quantify NOX in the exhaust. Use the CLD response as
the reference value. Also measure NMHC in the exhaust with a FID
analyzer that meets the specifications of subpart C of this part. Use
the FID response as the measured hydrocarbon value.
(3) Upstream of any sample dryer 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
[[Page 54962]]
line and to account for analyzer response.
(5) While all analyzers measure the sample's concentration, record
300 data points, 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
average NMHC concentration expected at the standard to the NMHC
concentration measured during the performance check.
(e) If the result of (7) is less than ±2%, then the
analyzer meets this interference check.
(f) You may use a NOX NDUV analyzer that demonstrates
±2% or greater H2O interference as long as you
meet all the following criteria:
(1) You try to correct the problem.
(2) The measurement deficiency does not affect your ability to show
that your engines comply with all applicable emission standards.
Sec. 1065.374 ZrO2 NOX analyzer NH3
interference and NO2 response checks.
(a) Scope and frequency. If you use a ZrO2 analyzer to
measure NOX, check for ammonia interference, NO2 response,
and operation under fuel rich conditions after installing the
ZrO2 analyzer and after major maintenance.
(b) Measurement principles. Ammonia (NH3) can positively
interfere with a ZrO2 analyzer by causing a response similar
to NOX. If your ZrO2 analyzer uses compensation
algorithms that utilize measurements of other gases to meet this
interference check, use those analyzers during the NH3
interference check. Because of the catalytic reactions required for
NOX measurement via ZrO2 analyzers, we specify an
NO2 response factor tolerance and an operational check under
net fuel-rich exhaust conditions.
(c) System requirements. A ZrO2 analyzer must have an
NH3 interference less than 2% of the flow-weighted average
concentration of NOX expected at the standard, though we
strongly recommend a lower interference of less than 1%. A
ZrO2 analyzer must also have an NO2 response
factor, RFNO2 of at least 0.95, but not more than 1.05, as
measured in paragraph (e) of this section.
(d) Ammonia interference check. Check for ammonia interference as
follows:
(1) Start, operate, zero, and span the NOX
ZrO2 analyzer according to the instrument manufacturer's
instructions.
(2) Select an NH3 span gas that meets the specifications
of Sec. 1065.750.
(3) Introduce the NH3 span gas at the inlet to the
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 the analyzer measures the sample's concentration, record
its output at its nominal frequency to record 300 data points.
Calculate the arithmetic mean of these 300 points.
(6) Multiply this mean by the ratio of expected NH3 to
span gas NH3 concentration. In other words, estimate the
flow-weighted average dry concentration of NH3 expected
during testing, and then divide this value by the concentration of
NH3 in the span gas used for this check. Then multiply this
ratio by the mean of the 300 values recorded during this check.
(e) If the result of paragraph (d)(6) is less than 2% of the flow-
weighted average concentration of NOX expected at the
standard, then the analyzer meets the interference check.
(f) You may use a NOX ZrO2 analyzer that does
not meet this performance check as long as you meet all the following
criteria:
(1) You try to correct the problem.
(2) The measurement deficiency does not affect your ability to show
that your engines comply with all applicable emission standards.
(g) NO2-response check. Check for NO2
response as follows:
(1) Select an NO2 calibration gas that meets the
specifications of Sec. 1065.750. Record the calibration concentration
of the gas.
(2) Start, operate, zero, and span the ZrO2 analyzer
according to the manufacturer's instructions.
(3) Introduce the NO2 calibration gas at the inlet of
the ZrO2 analyzer, and if you use an NO2 to NO
converter upstream of the analyzer during emission testing, introduce
the NO2 upstream of the NO2 to NO converter.
(4) Allow time for the analyzer response to stabilize.
Stabilization time may include time to purge the analyzer and to
account for detector response.
(5) While the analyzer measures the sample's concentration, record
its output at its nominal frequency to record 300 data points.
Calculate the arithmetic mean of these 300 points.
(6) Divide the mean measured value by the recorded calibration
concentration of the NO2 calibration gas. The result is the
ZrO2 analyzer's response factor for NO2.
(h) If the NO2 response factor is less than 0.95 or
greater than 1.05, take corrective action by repairing or replacing the
analyzer.
(i) Before using a ZrO2 analyzer for emission testing,
demonstrate that the corrective action resulted in an NO2
response factor of at least 0.95. Corrective action may include adding
an NO2 to NO converter to your emission testing system.
(j) You may use a NOX ZrO2 analyzer that has
an NO2 response factor greater than 1.05 as long as you meet
all the following criteria:
(1) You try to correct the problem.
(2) The measurement deficiency does not affect your ability to show
that your engines comply with all applicable emission standards.
(k) Oxygen debt check. If you use a NOX ZrO2
analyzer in exhaust that has oxygen, then you do not have to perform
this check. However, if you use a NOX ZrO2
analyzer in exhaust that has no oxygen and some CO and hydrocarbons,
then perform this check as follows:
(1) Start, operate, zero, and span the NOX
ZrO2 analyzer according to the instrument manufacturer's
instructions using a span gas that contains only NO and a balance gas.
The span gas must not contain CO or hydrocarbons.
(2) Select a tri-blend span gas of NO, CO and
C3H8 that meets the specifications of Sec.
1065.750, and record the NO concentration.
(3) Introduce the tri-blend span gas at the inlet to the 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 the analyzer measures the sample's concentration, record
its output at its nominal frequency to record 300 data points.
Calculate the arithmetic mean of these 300 points.
(l) If the mean calculated in paragraph (k)(5) of this section is
not within ±2% of the tri-blend NO concentration, take
corrective action by repairing or replacing the analyzer, or do not use
it to measure NOX in exhaust with an oxygen debt (i.e., net
fuel-rich exhaust).
(m) Before using a ZrO2 analyzer for emission testing in
exhaust that has an oxygen debt, demonstrate that corrective action
resulted in an oxygen debt check that returns a mean in paragraph
(k)(5) of this section of at least 98% of the tri-blend NO
concentration.
(n) You may use a NOX ZrO2 analyzer for
emission testing in exhaust that has an oxygen debt if the mean in
paragraph (k)(5) of this section is greater than 102% of the tri-blend
NO concentration as long as you meet all the following criteria:
(1) You try to correct the problem.
(2) The measurement deficiency does not affect your ability to show
that your engines comply with all applicable emission standards.
[[Page 54963]]
Sec. 1065.376 Chiller NO2 penetration.
(a) Scope and frequency. If you use a chiller to dry a sample
upstream of a NOX measurement instrument, but you don't use
an NO2 to NO converter upstream of the chiller, you must
perform this check. Perform this check after initial installation and
after major maintenance.
(b) Measurement principles. A chiller removes water, which can
otherwise interfere with a NOX measurement. However, liquid
water in an improperly designed chiller can remove NO2 from
the sample. Therefore, if a chiller is used without an NO2
to NO converter upstream, it could remove NO2 from the
sample prior to NOX measurement.
(c) System requirements. An chiller must meet the following
performance check so that at least 95% of the total NOX is
measured at the lowest expected NO/NOX fraction.
(d) Procedure. Use the following procedure to check the performance
of your chiller.
(1) Instrument setup. Follow the analyzer and chiller
manufacturers' start-up and operation instructions. Adjust the analyzer
and chiller as needed to optimize performance.
(2) Equipment setup. Connect an ozonator's inlet to a zero air
source and connect its outlet to one port of a 3-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 3-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) For the steps in paragraphs (d)(4) through (7) of this section,
set your analyzer to measure only NO (e.g., NO mode), or only read the
NO channel of your analyzer.
(4) Initial NOX adjustment. With the dewpoint generator
and the ozonator off, adjust the NO and zero gas flows so that the NO
concentration at the analyzer is at 2 times the peak total
NOX concentration expected during testing. Verify that gas
is flowing out of the overflow vent line.
(5) Total NOX adjustment. Turn on the dewpoint generator
and adjust its flow so that the NO concentration at the analyzer is at
the peak total NOX concentration expected during testing.
Verify that gas is flowing out of the overflow vent line.
(6) NO/NOX adjustment. Turn on the ozonator and adjust
the ozonator so that the NO concentration measured by the analyzer
decreases to represent the minimum NO/NOX fraction expected
during testing. Calculate this fraction as the NO concentration with
the ozonator on divided by the NO concentration with the ozonator off.
Determine your expected minimum fraction from previous emission tests
or estimate it based on good engineering judgment. For example, for a
stoichiometric spark-ignition engine, this minimum fraction may be (90
to 95)% NO/NOX; for a compression-ignition engine, this
minimum fraction may be (65 to 85)% NO/NOX. In the case of a
compression-ignition engine with an NO2 storage and
reduction aftertreatment system, this ratio may be (0 to 10)% NO/
NOX.
(7) If you cannot adjust the ozonator to achieve the expected
minimum NO/NOX fraction, select a higher concentration NO
span gas and repeat steps in paragraphs (d)(3) through (6). This will
increase the amount of zero air flow to the ozonator. If this solution
does not work, you may substitute the zero air with purified
O2.
(8) Data collection. Maintain the ozonator adjustment in paragraph
(d)(6) of this section, but turn off power to the ozonator.
(i) Switch the analyzer to measure total NOX
(NOX mode) or measure NOX as the sum of your
analyzer NO and NO2 readings.
(ii) Allow for stabilization, accounting for transport delays and
instrument response.
(iii) Calculate the mean of 25 samples from the analyzer and record
this value as NOxref.
(iv) Turn on the ozonator and allow for stabilization, accounting
for transport delays and instrument response.
(v) Calculate the mean of 25 samples from the analyzer and record
this value as NOxmeas.
(vi) Switch the ozonator off.
(vii) Repeat steps in paragraphs (d)(8)(i) through (vi) to record
seven values of NOxref and seven values of
NOxmeas.
(9) Performance evaluation. Calculate the means of the
NOXref and NOxmeas values. Divide the mean
NOxmeas by the mean NOxref. If the result is less
than 95%, repair or replace the chiller.
Sec. 1065.378 NO2-to-NO converter conversion check.
(a) Scope and frequency. If you use an analyzer that measures only
NO to determine NOX, you must use an NO2 to NO
converter upstream of the analyzer. Perform this check after installing
the converter and within six months after the last check. This check
must be repeated within six months of the check 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
NOX by converting the NO2 in exhaust to NO.
(c) System requirements. An NO2-to-NO converter must
meet the following performance check so that at least 95% of the total
NOX is measured at the lowest expected NO/NOX
fraction.
(d) Procedure. Use the following procedure to check the performance
of your NO2 to NO converter.
(1) Instrument setup. Follow the analyzer and NO2 to NO
converter manufacturers' start-up and operation instructions. Adjust
the analyzer and converter as needed to optimize performance.
(2) Equipment setup. Connect an ozonator's inlet to a zero air
source and connect its outlet to one port of a 4-way cross fitting.
Connect an NO span gas to another port of the cross. Connect the
NO2 to NO converter inlet to another port, and connect an
overflow vent line to the last port.
(3) Total NOX adjustment. With the NO2 to NO
converter in the bypass mode (e.g., NO mode) and the ozonator off,
adjust the NO and zero gas flows so that the NO concentration at the
analyzer is at the peak total NOX concentration expected
during testing. Verify that gas is flowing out of the overflow vent.
(4) NO/NOX adjustment. With the NO2 to NO
converter still in the bypass mode, turn on the ozonator and adjust the
ozonator so that the NO concentration measured by the analyzer
decreases to represent the minimum NO/NOX fraction expected
during testing. Calculate this fraction as the NO concentration with
the ozonator on divided by the NO concentration with the ozonator off.
Determine your expected minimum fraction from previous emission tests
or estimate it based on good engineering judgment. For example, for a
stoichiometric spark-ignition engine, this minimum fraction may be (90
to 95)% NO/NOX; for a compression-ignition engine, this
minimum fraction may be (65 to 85)% NO/NOX. In the case of a
compression-ignition engine with an NO2 storage and
reduction aftertreatment system, this ratio may be (0 to 10)% NO/
NOX.
(5) If you cannot adjust the ozonator to achieve the expected
minimum NO/NOX fraction, select a higher concentration NO
span gas and repeat steps in paragraphs (d)(3) and (4). This will
increase the amount of zero air flow to the ozonator. If this solution
does not
[[Page 54964]]
work, you may substitute the zero air with purified O2.
(6) Data collection. Maintain the ozonator adjustment in paragraph
(d)(4) of this section, but turn off power to the ozonator. Switch the
NO2 to NO converter from bypass mode to sample mode (e.g.,
NOX mode) so that the sample flows through the converter to
the analyzer.
(i) Allow for stabilization, accounting only for transport delays
and instrument response.
(ii) Calculate the mean of 25 samples from the analyzer and record
this value as NOxref.
(iii) Turn on the ozonator and allow for stabilization, accounting
only for transport delays and instrument response. Do not allow extra
stabilization time to account for NO2 to NO converter
response.
(iv) Calculate the mean of 25 samples from the analyzer and record
this value as NOxmeas.
(v) Switch the ozonator off.
(vi) Repeat the steps in paragraphs (d)(6)(i) through (v) of this
section to record seven values of NOxref and seven values of
NOxmeas.
(7) Performance evaluation. Calculate the means of the
NOxref and NOxmeas values. Divide the mean
NOxmeas by the mean NOxref. If the result is less
than 95%, repair or replace the NO2 to NO converter.
PM Measurements
Sec. 1065.390 PM balance and weighing process performance check.
(a) Scope and frequency. If you measure PM, check the balance
performance and the PM weighing environment as described in this
section within 12 h before weighing.
(b) Measurement principles. You must check balance performance by
zeroing and spanning it. Use calibration weights that meet the
specifications in Sec. 1065.790 to perform this check. You must also
check the PM-weighing environment and weighing process to make sure it
has not been compromised by improper balance operation, environmental
contamination, or some other problem with the weighing process.
(c) System requirements. Zero and span the balance. The reference
sample weighing procedure described in paragraph (e) of this section
must return a change in the reference samples' mean mass of no more
than ±10% of the net PM mass expected at the standard or
±10 [mu]g, whichever is higher, and ±10 mg if the
expected PM mass at the standard is not known. For example, a central
PM weighing lab might not have information about an applicable
standard, the amount of exhaust dilution, and the amount of exhaust
sampled to determine an expected value. If the reference sample
weighing procedure exceeds this threshold, invalidate all PM results
that were sampled after the last time the reference sample weighing
procedure was within these specifications.
(d) Procedure for checking balance performance. If you normally use
average values by repeating the weighing process to improve the
accuracy and precision of PM measurements, use the same process to
check balance performance using either of the following procedures. Use
an automated procedure to check balance performance if it meets the
intent described in paragraph (b) of this section. Otherwise use a
manual procedure in which you zero the balance and span the balance
with a calibration weight.
(e) Procedure for checking reference sample weighing procedures.
Check the reference sample weighing procedure as follows:
(1) Keep at least two unused PM sample media in the PM-
stabilization environment for use as reference samples. If you collect
PM with filters, select unused filters of the same medium and size for
use as reference samples. You may periodically replace reference
samples, using good engineering judgment.
(2) Stabilize reference samples. Consider reference samples
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 Sec. 1065.190(c) for at least the preceding 30
min.
(3) Exercise the balance several times with a reference sample. We
recommend weighing ten samples without recording values.
(4) Zero and span the balance.
(5) Weigh each of the reference samples and record the arithmetic
mean of their masses. We recommend using substitution weighing as
described in Sec. 1065.590(h). You may repeat weighing to improve
accuracy and precision.
(6) Record the balance environment dewpoint, ambient temperature,
and barometric pressure.
(7) Use the recorded ambient conditions to correct results for
buoyancy as described in Sec. 1065.690. Record the buoyancy-corrected
mean mass of the reference samples.
(8) Quantify the mean mass change of reference samples by
subtracting the buoyancy-corrected mean mass from the corresponding
value from the last time you checked PM weighing procedures under this
paragraph (e).
(f) If the reference samples' mean mass changes by more than 10% of
the net PM mass expected at the standard or by ±10 [mu]g,
whichever is greater, invalidate all PM results that were sampled after
the last time the reference sample weighing procedure was within this
specification. Before using a balance for emission testing, replace
reference samples and establish their mean mass.
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) We may select any engine configuration within the engine family
for our testing.
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.
(b) Run the test engine, with all emission-control systems
operating, long enough to stabilize emission levels. If you accumulate
50 h of operation for a spark-ignition engine or 125 h for a
compression-ignition engine, you may consider emission levels stable
without measurement. If the engine needs more operation to stabilize
emission levels, record your reasons and the methods for doing this,
and give us these records if
[[Page 54965]]
we ask for them. You may also use the provisions of Sec. 1065.10 to
request a shorter period of engine operation at which emission levels
may be considered stable without measurement.
(c) Do not service the test engine before you stabilize emission
levels, unless we approve such maintenance in advance. This prohibition
does not apply to your recommended oil and filter changes for newly
produced engines, or to idle-speed adjustments.
(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 fully loaded with fuel vapors before
running a test. Connect the canister's purge port to the engine and
plug the canister port that is normally connected to the fuel tank. Use
a canister and plumbing arrangement that represents the in-use
configuration of the largest capacity in all expected applications. 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 with an installed canister.
Sec. 1065.410 Maintenance limits for stabilized test engines.
(a) After you stabilize the test engine's emission levels, you may
do maintenance, other than during emission testing, as the standard-
setting part specifies. However, you may not do any maintenance based
on emission measurements from the test engine.
(b) Other than critical emission-related maintenance, you specify
in your application for certification, you must completely test an
engine for emissions before and after doing any maintenance that might
affect emissions, unless we waive this requirement.
(c) Unless we approve otherwise in advance, you may not use
equipment, instruments, or tools to identify bad engine components
unless you specify they should be used for scheduled maintenance on
production engines. In this case, if they are not generally available,
you must also make them available at dealerships and other service
outlets.
(d) You may adjust, repair, disassemble, or replace the test engine
only with our approval. We may approve these steps if all the following
occur:
(1) Something clearly malfunctions--such as persistent misfire,
engine stall, overheating, fluid leaks, or loss of oil pressure--and
needs maintenance or repair.
(2) You provide us an opportunity to verify the extent of the
malfunction before you do the maintenance.
(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 a
test engine. Also, if your test engine has a major mechanical failure
that requires you to take it apart, you may no longer use it as a test
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.
(a) Maintenance. The following limits apply to the maintenance that
we allow you to do on a test 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(b).
(b) Emission measurements. Perform emission tests following the
provisions of this part and the standard-setting part. 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--Running 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 by performing the following tasks:
(1) Map your engine by recording specified torque and speed data.
(2) Use your engine map to transform normalized duty cycles into
reference duty cycles for your engine.
(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.
(b) The general test consists of a duty cycle made of one or more
of the following segments (check the standard-setting part for specific
duty cycles):
(1) Either a cold-start transient cycle where you measure
emissions, or a warm-up cycle where you do not measure emissions.
Transient testing consists of a sequence of target values for speed and
torque that change continuously throughout the duty cycle.
(2) A hot-start transient test. Some duty cycles may omit engine
starting from the ``hot-start'' cycle.
(3) A steady-state test with a warmed-up engine. Steady-state tests
may involve discrete-mode testing or ramped-modal testing. Discrete-
mode testing consists of a series of discrete test modes with engine
operation stabilized at fixed speeds and torques, with separate
emission measurements for each mode. Ramped-modal testing consists of a
continuous time trace that includes a series of stable operating modes
connected by defined transitions, with a single emission measurement
for the whole cycle.
(c) Other subparts in this part identify how to select and prepare
an engine for testing (subpart E), perform the required engine service
accumulation (subpart E), and 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 values for engine speed and maximum brake torque.
Map your engine while it is connected to a dynamometer. 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. Map or re-map an engine before a test if any of the following
apply:
(1) You have not performed an initial engine map.
(2) The barometric pressure near the engine's air inlet is not
within 5% of the barometric pressure recorded at the time of the last
engine map.
(3) The engine or emission-control system has undergone changes
that might affect maximum torque performance.
(4) You capture an incomplete map on your first attempt or you do
not
[[Page 54966]]
complete a map within the specified time tolerance. You may repeat
mapping as necessary to capture a complete map within the specified
time.
(5) You may update an engine map at any time by repeating the
engine-mapping procedure.
(b) Mapping variable-speed engines. Map variable-speed engines as
follows:
(1) Record the barometric pressure.
(2) Warm up the engine by operating it at any speed and at
approximately 75% of the engine's expected maximum power until either
the engine coolant's temperature or block absolute temperature is
within ±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, no-load idle speed.
(4) Set operator demand to maximum and control engine speed at (95
±1)% of its warm, no-load idle speed for at least 15 s. For
engines with reference duty cycles whose lowest speed is greater than
warm, no-load idle speed, you may start the map at (95 ±1)%
of the lowest reference speed.
(5) Perform one of the following:
(i) For any naturally aspirated engine or for any engine subject
only to steady-state duty cycles, you may map it at discrete speeds by
selecting at least 20 evenly spaced setpoints between warm, no-load
idle and the highest speed above maximum mapped power at which (50 to
75)% of maximum power occurs. At each setpoint, stabilize speed and
allow torque to stabilize. Record the average speed and torque at each
setpoint. We recommend that you stabilize an engine for at least 15 s
at each setpoint and record the average feedback speed and torque of
the last (4 to 6) s. Use linear interpolation to determine intermediate
speed and torque values.
(ii) For any variable-speed engine, you may map it 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, no-load idle to the highest speed above maximum power at which
(50 to 75)% of maximum power occurs. 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 speed and torque values 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 (c) of this section without fuel, or with
minimum operator demand if operating without fuel would damage the
engine.
(3) Determine the amount of negative torque required to motor the
engine at the following two points: at warm, no-load idle and at the
highest speed above maximum power at which (50 to 75)% of maximum power
occurs. Operate the engine without fuel, or with minimum operator
demand if operating without fuel would damage the engine. Use linear
interpolation to determine intermediate values.
(d) Mapping constant-speed engines. For constant-speed engines,
generate a map as follows:
(1) Record the barometric pressure.
(2) Warm up the engine by operating it at any speed and at
approximately 75% of the engine's expected maximum power until either
the engine coolant's temperature or block 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. The installed governor may be an isochronous or a speed-droop
governor.
(4) With the governor or simulated governor controlling speed via
operator demand, operate the engine at no-load governed speed (at high
speed, not low idle) for at least 15 s.
(5) Record mean feedback speed and torque at 1 Hz or more
frequently and 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 speed and torque values 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) Test speed and test torque. Transform your duty cycles using
maximum test speed for variable-speed engines and maximum test torque
for constant-speed engines. You may declare maximum test speed before
mapping as long as it is within (97.5 to 102.5)% of its mapped value.
You may declare maximum test torque before mapping as long as it is
within (95 to 100)% of its mapped value. Otherwise, you must use the
measured value for transforming duty cycles.
(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 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, fntest, or speed may be
expressed by referring to a defined speed by name, such as ``warm, no-
load 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, fnref. 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.
(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, Tref. Section 1065.610 also describes under what
conditions
[[Page 54967]]
you may command Tref greater than the reference torque you
calculated from a normalized duty cycle. This provision permits you to
command Tref values representing curb-idle transmission
torque (CITT).
(3) Engine torque speed 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,
Tref. Section 1065.610 also describes under what conditions
you may command Tref greater than 0 Nm 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, fntest.
Section 1065.610 describes how to transform these normalized values
into a sequence of reference powers Pref. You may convert
these reference powers to reference speeds and torques for operator
demand and dynamometer control.
(c) Commands for variable-speed engines. Command reference speeds
and torques sequentially to perform a duty cycle. Update commands and
record reference and feedback values at a frequency of at least 5 Hz.
Use smooth transitions between reference values.
(d) Commands for constant-speed engines. Use dynamometer controls
to command reference torques sequentially for performing a duty cycle.
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. Update
commands and record reference and feedback values at a frequency of at
least 5 Hz. Use smooth transitions between reference values.
(e) Practice cycles. 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 a test engine's feedback
speeds and torques adequately matched the reference values in a duty
cycle. For any data required in this section, use the 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 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) Power. Before omitting any points under paragraph (e) of this
section, calculate feedback power, Pi and reference power,
Prefi, and calculate total work, W and reference work,
Wref, as described in Sec. 1065.650. Omit any points
recorded during engine cranking. Cranking includes any time when an
engine starter is engaged and any time when the engine is motored with
a dynamometer for the sole purpose of starting the engine. See Sec.
1065.525(a) and (b) for more information about engine cranking.
(e) Omitting additional points. In addition to omitting points
recorded during cranking, according to paragraph (d) of this section,
you may also omit certain points from duty cycle regression statistics,
which are also summarized in Table 1 of this section, as follows:
(1) When operator demand is at its minimum you may omit the
following points:
(i) Power and torque, if the reference torque is negative (i.e.,
engine motoring).
(ii) Power and speed, if the reference speed corresponds to an idle
command (0%), the reference torque corresponds to a minimum command
(0%), and the absolute value of the feedback torque is less than the
corresponding reference torque plus 2% of the maximum mapped torque.
(iii) Two out of three of power, torque, and speed if either
feedback speed or feedback torque is greater its reference command. You
may not omit a point from regression statistics if both feedback speed
and torque are greater than their reference commands.
(2) When operator demand is at its maximum, you may omit two out of
three of power, torque, and speed if either feedback speed or feedback
torque is less than its reference command. You may not omit a point
from regression statistics if both feedback speed and torque are less
than their reference commands.
Table 1 of Sec. 1065.514.--Summary of Point Omission Criteria From
Duty-Cycle Regression Statistics
------------------------------------------------------------------------
When operator demand is at
its . . . you may omit . . . if . . .
------------------------------------------------------------------------
minimum..................... power and torque.... Tref < 0.
minimum..................... power and speed..... fnref = idle (0%)
and Tref = minimum
(0%) and T < Tref
± 2%
Tmax mapped.
minimum..................... 2 out of 3 of power, fn > fnref or T >
torque, and speed. Tref but not if fn
> fnref and T >
Tref.
maximum..................... 2 out of 3 of power, fn < fnref or T <
torque, and speed. Tref but not if fn
< fnef and T <
Tref.
------------------------------------------------------------------------
(f) Use the remaining points to calculate regression statistics
described in Sec. 1065.602, as follows:
(1) Slopes for feedback speed, a1fn, feedback torque,
a1T, and feedback power a1P.
(2) Intercepts for feedback speed, a0fn, feedback
torque, a0T, and feedback power a0P.
(3) Standard estimates of error for feedback speed,
SEfn, feedback torque, SET, and feedback power
SEP.
(4) Coefficients of determination for feedback speed,
r2fn, feedback torque, r2T, and
feedback power r2P.
(g) Cycle statistics. Unless the standard-setting part specifies
otherwise, use the following criteria to validate a duty cycle:
[[Page 54968]]
(1) For variable-speed engines only, feedback total work must be at
or below 105% of reference total work.
(2) For variable-speed engines only, apply all the statistical
criteria in Table 2 of this section.
(3) For constant-speed engines, apply the statistical criteria only
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, < =a0< =.. < = 10% of warm idle.... < = 2% of maximum mapped < = 2% of maximum mapped
torque. power.
Standard error of estimate, SE....... < = 5% 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 in Sec.
1065.590.
(b) Unless the standard-setting part specifies different values,
verify that ambient conditions before the test are within the following
tolerances:
(1) Ambient temperature of (20 to 30) [deg]C.
(2) Barometric 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 humidity.
(d) You may perform a final calibration of the speed, torque, and
proportional-flow control systems, which may include performing
practice duty cycles.
(e) 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 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 performance checks on any idle
equipment or analyzers during preconditioning.
(7) Proceed with the test sequence described in Sec.
1065.530(a)(1).
(f) HC contamination check. After the last practice or
preconditioning cycle before an emission test, check for contamination
in the HC sampling system as follows:
(1) Select the HC analyzer range for measuring the flow-weighted
average concentration expected at the HC standard.
(2) Zero the HC analyzer using zero air introduced at the analyzer
port.
(3) Span the HC analyzer using span gas introduced at the analyzer
port. Span 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.
(4) Overflow zero air at the HC probe or into a fitting between the
HC probe and the 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,
xHCinit, and use it to correct measured values as described
in Sec. 1065.660.
(7) If xHCinit exceeds the greatest of the following
values, determine the source of the contamination and take corrective
action, such as purging the system or replacing contaminated portions:
(i) 2% of the flow-weighted average concentration expected at the
standard or measured during testing, whichever is greater.
(ii) 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 a fully charged battery or a 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.
Accelerate the engine to cranking speed within ± 25% of the
time it would take with an in-use engine. Stop cranking within 1 s of
starting the engine.
(b) If the engine does not start after 15 s 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 other time after emission sampling
begins, the test is void.
(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(d):
(i) For cold-start duty cycles, shut down the engine. Unless the
standard-setting part specifies otherwise, you may use forced cooling
to stabilize the temperature of the engine and any aftertreatment
systems. You may start a cold-start duty cycle when the temperatures of
an engine's lubricant, coolant, and aftertreatment systems are 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 steady-state testing, you may continue to operate
the engine at fntestand 100% torque if that is the first operating
point. Otherwise, operate the
[[Page 54969]]
engine at warm, no-load idle or the first operating point of the duty
cycle. In any case, start the duty cycle 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, start the engine and the duty cycle
when the temperatures of an engine's lubricant, coolant, and
aftertreatment systems are between (20 and 30) [deg]C. Unless the
standard-setting part specifies otherwise, you may use forced cooling
to stabilize the temperature of the engine and any aftertreatment
system.
(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 temperature or block
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, no-load idle or the
first operating point of the duty cycle. Start the test within 10 min
of achieving temperature stability. You may determine temperature
stability either as the point at which the engine coolant temperature
or the block absolute temperature is within 2% of its mean value for at
least 2 min, or 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.
(3) Start dilution systems, sample pumps, cooling fans, and the
data-collection system.
(4) Preheat any heat exchangers in the sampling system.
(5) Allow heated components such as sample lines, filters, and
pumps to stabilize at operating temperature.
(6) Perform vacuum-side leak checks as specified in Sec. 1065.345.
(7) Using bypass, adjust the sample flow rates to desired levels.
(8) Zero any integrating devices.
(9) Zero and span all constituent analyzers using NIST-traceable
gases that meet the specifications of Sec. 1065.750. Span flame
ionization detector 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.
(10) If you correct for dilution air background concentrations of
engine exhaust constituents, start measuring and recording background
constituent 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, simultaneously start running the duty
cycle, sampling exhaust gases, recording data, and integrating measured
values.
(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) Before 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 on the data-collection medium.
(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) 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.
(2) As soon as practical after the duty cycle is complete, analyze
any gaseous batch samples, including background samples.
(3) After quantifying exhaust gases, check drift as follows:
(i) 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. 1065.657.
(h) Determine if the test meets the validation criteria in Sec.
1065.514.
Sec. 1065.545 Validation of proportional flow control for batch
sampling.
For any proportional batch sample such as a bag sample or PM filter
sample, demonstrate that proportional sampling was maintained using one
of the following:
(a) Record the sample flow rate and the total flow rate at 1 Hz or
more frequently. Use this data with the statistical calculations in
Sec. 1065.602 to determine the standard error of the estimate, SE, of
the sample flow rate versus the total flow rate. For each test
interval, demonstrate that SE was less than or equal to 3.5% of the
mean sample flow rate. You may omit up to 5% of the data points as
outliers to improve SE.
(b) Record the sample flow rate and the total flow rate at 1 Hz or
more frequently. For each test interval, demonstrate that each flow
rate was constant within ±2.5% of its respective mean or
target flow rate.
(c) For critical-flow venturis, record venturi-inlet conditions at
1 Hz or more frequently. Demonstrate that the density at the venturi
inlet 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
temperature over each test interval.
(d) For positive-displacement pumps, record pump-inlet conditions
at 1 Hz or more frequently. 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 temperature over
each test interval.
(e) Using good engineering judgment, demonstrate using an
engineering analysis that the proportional-flow control system
inherently ensures proportional sampling under all circumstances
expected during testing. For example, you use CFVs for sample flow and
total flow and their inlet pressures and temperatures are always the
same as each others, and they always operate under critical-flow
conditions.
Sec. 1065.550 Constituent analyzer range validation, drift
validation, and drift correction.
(a) Check the results of all analyzers that do not have auto-
ranging capability to determine if any results show that an analyzer
operated above 100% of its
[[Page 54970]]
range. 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 nearest
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. Report all
results.
(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. Report all results.
(b) Calculate and correct for drift as described in Sec. 1065.657.
Drift invalidates a test if the drift correction exceeds ±4%
of the flow-weighted average concentration expected at the standard or
measured during a test interval, whichever is greater.
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 performance checks 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 a 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 (i) 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) 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 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 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, this
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
barometric pressure.
(6) Reweigh the calibration weight and record the stable balance
reading.
(7) Calculate the arithmetic mean of the two calibration-weight
readings 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.
(8) Repeat the steps in paragraphs (i)(1) through (7) of this
section for additional unused sample media.
(j) If you use filters as sample media, load unused filters that
have been tare-weighed into 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.
Depending upon your cassette material, ethanol might be an acceptable
solvent.
Sec. 1065.595 PM sample post-conditioning and total weighing.
(a) Make sure the balance and PM-stabilization environments meet
the periodic performance checks in Sec. 1065.390.
(b) In the PM-stabilization environment, remove PM samples from
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. Consider a sample 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. Alternatively, for engines subject to
PM standards above 0.05 g/kW-hr, you may consider a sample medium
stabilized after 60 min.
(f) Repeat the procedures in Sec. 1065.590(f) through (h) to weigh
used PM samples, but 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,
mPM. Use mPM in emission calculations in Sec.
1065.650.
Subpart G--Calculations and Data Requirements
Sec. 1065.601 Overview.
(a) This subpart describes how to use the signals recorded before,
during, and after an emission test to calculate brake-specific
emissions of each regulated constituent.
(b) You may use data from multiple systems to calculate test
results, consistent with good engineering
[[Page 54971]]
judgment. We allow weighted averages where appropriate. You may discard
statistical outliers, but you must report all results.
(c) Calculations for some calibrations and performance checks are
in this subpart.
(d) Statistical values are defined in this subpart.
Sec. 1065.602 Statistics.
(a) 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,
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Example:
[Ngr]
= 3
[gamma]1 = 10.60
[gamma]2 = 11.91
[gamma][Ngr] = [gamma]3 = 11.20
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(c) Standard deviation. Calculate a non-biased (e.g., N-1) sample
standard deviation, [sigma], as follows:
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Example:
[Ngr]=3
[gamma]1=10.60
[gamma]2=11.91
[gamma][Ngr]=[gamma]3=11.09
[gamma]=11.20
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(d) Root mean square. Calculate a root mean square,
rms[gamma], as follows:
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Example:
[Ngr]=3
[gamma]1=10.60
[gamma]2=11.91
[gamma][Ngr]=[gamma]3=11.09
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(e) Accuracy. Calculate an accuracy, as follows, noting that the
[gamma]i are arithmetic means, each determined by repeatedly
measuring one sample of a single reference quantity,
[gamma]ref.
accuracy = [bond][gamma]ref - [gamma][bond]
Example:
[gamma]ref = 1800.0
([Ngr]
= 10)
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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, [ngr], as follows:
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TP10SE04.019
Example:
[gamma]ref=1205.3
[gamma]=1123.8
[sigma]ref=9.399
[sigma][gamma]=10.583
[Ngr]ref=11
[Ngr]=7
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Example:
[sigma]ref=9.399
[Ngr]ref=11
[sigma][gamma]=10.583
[Ngr]=7
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TP10SE04.024
(2) For a paired t-test calculate the t statistic and its number of
degrees of freedom, [ngr], as follows, noting that the
[egr]i are the errors (e.g., differences) between each pair
of yrefi and yi:
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Example:
[egr]=0.12580
N=16
[sigma][egr]=0.04837
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[ngr]
= N - 1
Example:
[Ngr]
= 16
[ngr]
= [Ngr]
- 1
[ngr]
= 15
[[Page 54972]]
(3) Use Table 1 of this section to compare t to the
tcrit values tabulated versus the number of degrees of
freedom. If t is less than tcrit, then t passes the t-test.
Table 1 of Sec. 1065.602-Critical t Values Versus Number of Degrees of
Freedom, v
------------------------------------------------------------------------
tcrit versus v
-------------------------------------------------------------------------
Confidence
------------------------------------------------------------------------
v 90% 95%
------------------------------------------------------------------------
1............................................. 6.314 12.706
2............................................. 2.920 4.303
3............................................. 2.353 3.182
4............................................. 2.132 2.776
5............................................. 2.015 2.571
6............................................. 1.943 2.447
7............................................. 1.895 2.365
8............................................. 1.860 2.306
9............................................. 1.833 2.262
10............................................ 1.812 2.228
11............................................ 1.796 2.201
12............................................ 1.782 2.179
13............................................ 1.771 2.160
14............................................ 1.761 2.145
15............................................ 1.753 2.131
16............................................ 1.746 2.120
18............................................ 1.734 2.101
20............................................ 1.725 2.086
22............................................ 1.717 2.074
24............................................ 1.711 2.064
26............................................ 1.706 2.056
28............................................ 1.701 2.048
30............................................ 1.697 2.042
35............................................ 1.69 2.03
40............................................ 1.684 2.021
50............................................ 1.676 2.009
70............................................ 1.667 1.994
100........................................... 1.66 1.984
INF........................................... 1.645 1.96
------------------------------------------------------------------------
(g) F-test. Calculate the F statistic as follows:
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Example:
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(1) For a 90% confidence F-test, use Table 2 of this section to
compare F to the Fcrit90 values tabulated versus N minus one
(N-1) and Nref minus one (Nref-1). If F is less
than Fcrit90, then F passes the F-test at 90% confidence.
(2) For a 95% confidence F-test, use Table 3 of this section to
compare F to the Fcrit95 values tabulated versus N minus one
(N-1) and Nref minus one (Nref-1). If F is less
than Fcrit95, then F passes the F-test at 95% confidence.
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(h) Slope. Calculate a least-squares regression slope, as follows:
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Example:
N = 6000
y 1 = 2045.8
y ref 1 = 2045.0
y = 1050.1
y ref = 1055.3
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TP10SE04.038
(i) Intercept. Calculate a least-squares regression intercept,
a[Ogr]y as follows:
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Example:
y = 1050.1
a1y = 1.0110
yref = 1055.3
a[Ogr]y = 1050.1-(1.0110[middot]1055.3)
a[Ogr]y = -16.8083
(j) Standard estimate of error. Calculate a standard estimate of
error, SE, as follows:
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Example:
N = 6000
y1 = 2045.8
aoy = 16.8083
a1y = 1.0110
yref 1 = 2045.0
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TP10SE04.042
(k) Coefficient of determination. Calculate a coefficient of
determination, r2, as follows:
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Example:
N = 6000
y1 = 2045.8
aoy = 16.8083
a1y = 1.0110
yref 1 = 2045.0
y = 1480.5
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TP10SE04.045
(1) Flow weighted average concentration. A flow-weighted average
means the average 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 average concentration is the sum of the products of each
recorded concentration times its respective exhaust flow rate, divided
by the number of recorded values. As another example, the bag
concentration from a CVS system is the same as the flow-weighted
average concentration because the CVS system itself flow-weights the
bag concentration. You might already expect a certain flow weighted
average concentration of an emission at its standard based on previous
testing with similar engines or testing with similar equipment and
instruments. If you need to estimate your expected flow weighted
average concentration of an emission at its standard, we recommend
using the following examples as a guide for how to estimate the flow
weighted average concentration expected at a standard. Note that these
examples are not exact and that they contain assumptions that are not
always valid. Use good engineering judgement to determine if you can
use similar assumptions.
(1) To estimate the flow weighted average raw exhaust
NOX concentration from a turbo-charged heavy-duty
compression-ignition engine at a NOX standard of 2.5 g/kWhr,
you may do the following:
(i) Based on your engine design, approximate a maximum torque
versus speed map and use it with the applicable normalized duty cycle
in the standard-setting part to generate a reference duty cycle as
described in Sec. 1065.610. Calculate the total reference work,
Wref, as described in Sec. 1065.650. Divide the reference
work by the duty cycle's time interval, [Delta]tduty cycle
to determine average reference power, Pref.
(ii) Based on your engine design, estimate maximum power,
Pmax, the design speed at maximum power, fnmax,
and the design maximum intake manifold boost pressure,
Pinmax and temperature Tinmax. Also estimate an
average fraction of power that is lost due to friction and pumping,
Pfrict. Use this information along with the engine
displacement volume, Vdisp, an
[[Page 54976]]
approximate volumetric efficiency, [eta]V, and the number of engine
power strokes per cycle (e.g., 2-stroke or 4-stroke) to estimate the
maximum raw exhaust flow rate, nexhmax.
(iii) Use your estimated values as described in the following
example calculation:
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Example:
eNOx=2.5 g/(kW[middot]hr)
Wref=11.883 kW[middot]hr
[Delta]tduty cycle=20 min
MNOx=46.0055 g/mol
Pref=35.65 kW
Pmax=125 kW
Pfrict=15%
[eta]v=0.9
pmax=300 kPa
Vdisp=3.0 l
fnmax=2800 rev/min
Nstroke=4 1/rev
R=8.314472 J/(mol[middot]K)
Tmax=348.15 K
Cp=1000 Pa/kPa
Cv=1000 l/m3
Ct=60 s/min
Cmol=1000000 [mu]mol/mol
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TP10SE04.048
(2) To estimate the flow weighted average NMHC concentration in a
CVS from a naturally aspirated nonroad spark-ignition engine at an NMHC
standard of 0.5 g/kW[middot]hr, you may do the following:
(i) Based on your engine design, approximate a maximum torque
versus speed map and use it with the applicable normalized duty cycle
in the standard-setting part to generate a reference duty cycle as
described in Sec. 1065.610. Calculate the total reference work,
Wref, as described in Sec. 1065.650.
(ii) Multiply your CVS total flow rate by the time interval of the
duty cycle, [Delta]tduty cycle. The result is the total
diluted exhaust flow of the ndexh.
(iii) Use your estimated values as described in the following
example calculation:
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Example:
eNMHC=1.5 g/(kW[middot]hr)
Wref=5.389 kW[middot]hr
MNMHC=13.875389 g/mol
dexh=6.021 mol/s
[Delta]tduty cycle=30 min
Ct=60 s/min
Cmol=1000000 [mu]mol/mol
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TP10SE04.051
Sec. 1065.605 Field test system overall performance check.
(a) This section contains equations and example calculations for
statistics that are specified in Sec. 1065.920 for field-testing
systems. In this section we use the letter ``e'' to denote the brake-
specific emissions of a test interval, the superscript over-bar
``-'' to denote an arithmetic mean, the subscript
``lab'' to denote a laboratory result, and the subscript
``field'' to denote a field-testing result.
(b) Assume that the brake-specific data in the following table was
collected by performing the overall field test system check as
described in Sec. 1065.920.
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(c) For example, calculate for the first test interval
efield 1, elab 1, and [Delta]e1 /
elab std , and as follows:
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TP10SE04.055
similarly,
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[Delta]e1 / elab std = (efield 1 -
elab 1) / elab std
elab std = 2.50 g / kW[middot]hr
[Delta]e1 / elab std = (2.17 - 2.07) / 2.50
[Delta]e1 / elab std = 4.0%
(d) For example, calculate for the second test interval
UCLfield 2, UCLlab 2,
[Delta]UCL 2 as follows:
UCLfield 2 = e< field 2 +
2? [sigma]e field 2
see 1065.602(c) for [sigma]e field 2?
For UCL, recalculate e< field 2 and [sigma]
e field 2
after applying measurement allowance.
Example:
measurement allowance = 0.95
UCLfield 2 = 3.258 + 2? 0.278
[[Page 54978]]
UCLfield 2 = 3.81 g / kWlab 2 = 3.500 + 2? 0.216
UCLlab 2 = 3.93 g / kW2 = UCLfield 2-UCLlab 2
[Delta]UCL2 = 3.81 -3.93
[Delta]UCL2 = -0.12 g / kWntest and maximum test torque
Ttest. For all engines, calculate test speed from the power
versus speed map generated as per Sec. 1065.510.
(1) Based on the power versus speed map, determine the maximum
power and the speed at which maximum power occurred. Divide each
recorded power by the maximum power and divide each recorded speed by
the speed at which maximum power occurred. The resulting data set is a
normalized data set of power versus speed. Use this data set to
determine test speed. Test speed is the speed at which the normalized
data set returns a maximum value of the sum of the squares of
normalized speed and normalized power.
(2) For example:
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Example:
fn@Pmax = 2355 rev/min
fnnorm1 = 1.002, Pnorm1 = 0.978
fnnorm2 = 1.004, Pnorm2 = 0.977
fnnorm3 = 1.006, Pnorm3 = 0.974
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fntest = 2355? [1.004]
= 2364 rev/min
(3) For variable-speed engines, use this measured test speed--or
your declared test speed as described in Sec. 1065.510--to transform
normalized speeds to reference speeds as described in paragraph (b) of
this section.
(4) For constant-speed engines, use the torque corresponding to
this measured test speed as measured test torque--or your declared test
torque as described in Sec. 1065.510--to transform normalized torques
to reference torques as described in paragraph (c) of this section.
(b) Speed. Transform normalized speed values to reference values as
follows:
(1) % speed. If your normalized duty cycle specifies % speed
values, use your declared warm no-load idle speed and your test speed
to transform the duty cycle, as follows:
fnref = % speed? (fntest -fnidle) +
fnidle
Example:
% speed = 85%
fntest = 2364 rev/min
fnidle = 650 rev/min
fnref = 85%? (2364 -650) + 650
fnref = 2107 rev/min
(2) A, B, and C speeds. If your normalizsed duty cycle specifies
speed values as A, B, or C values, use your power versus speed curve to
determine the lowest speed below maximum power at which 50% of maximum
power occurs. Denote this value as nlo. Also determine the
highest speed above maximum power at which 70% of maximum power occurs.
Denote this value as nhi. Use nhi and
nlo to calculate reference values for A, B, or C speeds as
follows:
fnrefA = 0.25? (nhi -nlo) +
nlo
fnrefB = 0.50? (nhi -nlo) +
nlo
fnrefC = 0.75? (nhi -nlo) +
nlo
Example:
nlo = 1005 rev/min
nlo = 2385 rev/min
fnrefA = 0.25? (2385 -1005) + 1005
fnrefB = 0.50? (2385 -1005) + 1005
fnrefC = 0.75? (2385 -1005) + 1005
fnrefA = 1350 rev/min
fnrefB = 1695 rev/min
fnrefC = 2040 rev/min
(3) Intermediate speed. If your normalized duty cycle specifies a
speed as ``intermediate speed'', use your torque versus speed curve to
determine the speed at which maximum torque occurs.
(i) Determine the speed at which peak torque occurs. This is peak
torque speed.
(ii) If peak torque speed is between (60 to 75) % of test speed,
then your reference intermediate speed is peak torque speed.
(iii) If peak torque speed is less than 60% of test speed, then
your reference intermediate speed is 60% of test speed.
(iv) If peak torque speed is greater than 75% of test speed, then
your reference intermediate speed is 75% of test speed.
(c) Torque. Transform normalized torque values to reference values
using your maximum torque versus speed map. For variable-speed engines
you must first transform normalized speed values into reference speed
values. For constant-speed engines, you need only your test torque
value.
(1) % torque for variable-speed engines. For a given speed point,
multiply the corresponding % torque by the maximum torque at that
speed, according to your map. Linearly interpolate mapped torque values
to determine torque between mapped speeds. The result is the reference
torque for that speed point.
(2) % torque for constant-speed engines. Multiply a % torque value
by your test torque. The result is the reference torque for that point.
(3) Permissible deviations for any engine. If your engine does not
operate in-use below a certain torque under certain conditions, you may
use a declared minimum torque as the reference value instead of the
value calculated in paragraph (c)(1) or (2) of this section. For
example, if your engine is connected to an automatic transmission, it
may have a minimum torque called curb idle transmission torque (CITT).
In this case, at idle conditions (i.e., 0% speed, 0% torque), you may
use CITT as a reference value instead of 0 N[middot]m.
(d) Power. Transform normalized power values to reference speed and
[[Page 54979]]
torque values using your maximum power versus speed map. For variable-
speed engines you must first transform normalized speed values into
reference speed values. For constant-speed engines, you need only your
maximum power value.
(1) % power for variable-speed engines. For a given speed point,
multiply the corresponding % power by the maximum power of your entire
map. The result is the reference power for that speed point. You may
calculate a corresponding reference torque for that point and command
that reference torque instead of a reference power.
(2) % torque for constant-speed engines. Multiply a % power value
by the maximum power of your entire map. The result is the reference
power for that point. You may calculate a corresponding reference
torque for that point and command that reference torque instead of a
reference power.
(3) Permissible deviations for any engine. If your engine does not
operate in-use below a certain power under certain conditions, you may
use a declared minimum power as the reference value instead of the
value calculated in paragraph (d)(1) or (2) of this section. For
example, if your engine is directly connected to a propeller, it may
have a minimum power called idle power. In this case, at idle
conditions (i.e., 0% speed, 0% torque), you may use a corresponding
idle torque as a reference torque instead of 0 N[middot]m.
Sec. 1065.630 1980 International Gravity Formula.
Calculate the acceleration of Earth's gravity at your latitude, as
follows:
ag = 9.7803267715x
(1+5.2790414E-03xsin([thetas])\2\ + 2.32718E-
05xsin([thetas])4
+1.262E-07xsin([thetas])\6\ + 7E-10xsin([thetas])8)
Example:
[thetas]
= 45[deg]
ag = 9.7803267715x
(1+5.2790414E-03xsin(45)2 + 2.32718E-05xsin(45)4
+1.262E-07xsin(45)6 + 7E-10xsin(45)\8\)
ag = 9.8178291229 m/s2
Sec. 1065.640 PDP and venturi (SSV and CFV) calibration calculations.
(a) Reference meter conversions. The following calibration
equations use molar flow rate, nref as a reference quantity.
If your reference meter outputs a flow rate in a different quantity
such as standard volume rate, Vstdrefactual volume rate,
Vactrefor mass rate, mref, convert your reference
meter output to molar flow rate using the following:
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Examples:
Vstdref =1000.00 ft \3\/min
Tstd = 68.0 [deg]F
R = 8.314472 J/(mol[middot]K)
CT = (T + 459.67)/1.8 K/[deg]F
CV = 35.314662 ft \3\/m \3\
Ct = 60 s/min
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mref = 17.2683 kg/mih
Mmix = 28.7805 g/mol
Cm = 1000 g/kg
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(b) PDP calibration calculations. For each restrictor position,
calculate the following values, from the mean values determined in
Sec. 1065.340, as follows:
(1) PDP volume pumped per revolution, Vrev m \3\/rev:
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Example:
nref = 25.096 mol/s
R = 8.314472 J/mol[middot]K
Tin = 299.5 K
Pin = 98.290 kPa
fPDP = 1205.1 rev/min
Ct = 60 s/min
Cp = 1000 (J/m \3\)/kPa
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(2) PDP slip correction factor, Ks s/rev:
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Example:
fPDP = 1205.1 rev/min
Pout = 100.103 kPa
Pin = 98.290 kPa
Ct = 60 s/min
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(3) Perform a least-squares regression of PDP volume pumped per
revolution, Vrev versus PDP slip correction factor, Ks, by calculating
slope, a1 and intercept a0 as described in Sec. 1065.602.
(4) Repeat the procedure in paragraphs (a)(1) through (3) of this
section for every speed that you run your PDP.
(5) Use the slopes and intercepts to calculate flow rate during
emission testing as described in Sec. 1065.642.
(c) Venturi governing equations and allowable assumptions. Because
a subsonic venturi (SSV) and a critical-flow venturi (CFV) both operate
similarly, their governing equations are the same, except for the
equation describing their pressure ratio r (i.e., rSSV
versus rCFV). The following symbols are used for the
following quantities in subsequent calculations:
At = venturi throat cross-sectional area
Cd = discharge coefficient
Cf = flow coefficient
Cm = mass conversion factor
Cp = pressure conversion factor
dt = venturi throat diameter
Mmix = molar mass of gas mixture
n = molor flow rate
pin = venturi inlet absolute static pressure
r = pressure ratio
Tin = venturi inlet absolute temperature
Z = compressibility factor
[beta]
= ratio of venturi throat to inlet diameters
[Delta]p = differential static pressure; venturi inlet minus venturi
throat
[gamma]
= ratio of specific heats of gas mixture
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(1) You may iterate to solve for rCFV and subsequently
calculate Cf for a CFV, CfCFV, or you may
determine CfCFV from Table 1 of Sec. 1065.640, based on
your [beta]
and [gamma].
Table 1 of Sec. 1065.640.--CfCFV versus [beta]
and [gamma]
------------------------------------------------------------------------
CfCFV
-------------------------------------------------------------------------
[gamma]dexh
[gamma]exh =
[beta]
= 1.385 [gamma]air
= 1.399
------------------------------------------------------------------------
0.000......................................... 0.6822 0.6846
0.400......................................... 0.6857 0.6881
0.500......................................... 0.6910 0.6934
0.550......................................... 0.6953 0.6977
0.600......................................... 0.7011 0.7036
0.625......................................... 0.7047 0.7072
0.650......................................... 0.7089 0.7114
0.675......................................... 0.7137 0.7163
0.700......................................... 0.7193 0.7219
0.720......................................... 0.7245 0.7271
0.740......................................... 0.7303 0.7329
0.760......................................... 0.7368 0.7395
0.770......................................... 0.7404 0.7431
0.780......................................... 0.7442 0.7470
0.790......................................... 0.7483 0.7511
0.800......................................... 0.7527 0.7555
0.810......................................... 0.7573 0.7602
0.820......................................... 0.7624 0.7652
0.830......................................... 0.7677 0.7707
0.840......................................... 0.7735 0.7765
0.850......................................... 0.7798 0.7828
------------------------------------------------------------------------
(2) Permissible assumptions. You may make several simplifying
assumptions of the governing equations.
(i) For emission testing over the full ranges of raw exhaust,
diluted exhaust and dilution air, you may assume that the gas mixture
behaves as an ideal gas: Z = 1.
(ii) For the full range of raw exhaust you may assume a constant
ratio of specific heats of [gamma]
= 1.385.
(iii) For the full range of diluted exhaust and air (e.g.,
calibration air or dilution air), you may assume a constant ratio of
specific heats of [gamma]
= 1.399.
(iv) For the full range of diluted exhaust and air, you may assume
the molar mass of the mixture is a function only of the amount of water
in the dilution air or calibration air, xH2O, determined as
described in Sec. 1065.645, as follows:
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Example:
Mair = 28.96559 g/mol
xH2O = 0.0169 mol/mol
MH2O = 18.01528 g/mol
MMIX=28.96559 [middot]
(1-0.0169)+18.01528[middot]0.0169
MMIX28.7805 g/mol
(v) For the full range of diluted exhaust and air, you may assume a
constant molar mass of the mixture, Mmix such that the
assumed molar mass differs from the actual molar mass by no more than
± 1% for all calibration and all testing. This might occur
if you sufficiently control the amount of water in calibration air and
in dilution air, and this might occur if you remove sufficient water
from both calibration air and dilution air. Table 2 of this section
gives examples of permissible emission testing dilution air dewpoints
versus calibration air dewpoints.
Table 2. of Sec. 1065.640.--Permissible Ranges of Dilution Air
Dewpoint Versus Calibration Dewpoint Where a Constant Mmix May Be
Assumed
------------------------------------------------------------------------
Assume
If calibration Tdew constant For emissions test
Mmix Tdew range a
------------------------------------------------------------------------
[deg]C............................. g/mol [deg]C
dry................................ 28.96559 dry to 18
0.................................. 28.89263 dry to 21
5.................................. 28.86148 dry to 22
10................................. 28.81911 dry to 24
15................................. 28.76224 dry to 26
20................................. 28.68685 -8 to 28
25................................. 28.58806 12 to 31
30................................. 28.46005 23 to 34
------------------------------------------------------------------------
a Range valid for all calibration and emissions testing over the
barometric pressure range (80.000 to103.325) kPa.
(3) Calibration equation for SSV and CFV. For each data point
collected in Sec. 1065.340, solve for Cd. The following
example illustrates the use of the governing equations for the SSV.
Note that for the case of the CFV, the equation for Cd would
be the same. However, for Cf you would use your values of
[Beta]
and [gamma]
to determine Cf iteratively as described
in paragraph (b)(1) of this section, or you would look up a constant
value of Cf for all calibration and testing in Table 1 of
Sec. 1065.640.
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Example:
nref = 57.625 mol/s
Z = 1
Mmix = 28.7805 g/mol
R = 8.314472 J/mol[middot]K
Tin = 298.15 K
At = 0.01824 m2
Pin = 99.132 kPa
[gamma]
= 1.399
[beta]
= 0.8
[Delta]p = 2.312 kPa
Cm = 1000 g/kg
Cp = Pa/kPa
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(i) SSV calibration. For each data point collected in Sec.
1065.340, also calculate Re# at the throat of the
venturi. Because the dynamic viscosity, [mu]. is needed to compute
Re#, you may use your own fluid viscosity model to
determine [mu], using good engineering judgment. Alternatively, you may
use the Sutherland three coefficient viscosity model for air at
moderate pressures and temperatures. An example of this is shown in the
following example calculation for Re#:
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Sutherland model:
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[mu][ogr] =1.7894[middot]10-\5\ kg/(m[middot]s)
[Tgr][ogr] = 273.11 [Kappa]
S = 110.56 [Kappa]
Example:
[Mu]mix = 28.7805 g/mol
[eta]ref = 57.625 mol/s
d[tgr] = 0.1524 m
[Tgr]in = 298.15 [Kappa]
Cm = 1000 g/kg
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(ii) Create a regression equation to calculate Cd versus
Re#. You may use any mathematical expression such as
a least-square polynomial or a power series. The regression equation
must cover the flow range of Re# expected during
testing.
(iii) The regression equation must predict Cd values within < plus-
minus>0.5% of the individual Cd values determined from calibration.
(iv) If the ±0.5% criterion is met, transfer the
regression equation to the SSV real time calculation system for use in
emission tests as described in Sec. 1065.642. Do not use the equation
beyond the upper and lower calibration points used to determine the
equation.
(v) If the ±0.5% criterion is not met for an individual
data point, based upon good engineering judgment, you may omit data
points and recalculate the regression equation, provided you use at
least 7 points that meet the criterion. Do not use the equation beyond
the upper and lower calibration points used to determine the equation.
If omitting points does not resolve outliers, take corrective action.
For example, check for leaks or repeat the calibration process. If you
must repeat the process, we recommend applying tighter tolerances to
measurements and allow more time for flows to stabilize.
(vi) CFV calibration. Calculate the mean and standard deviation of
all the Cd as described in Sec. 1065.602. If the standard deviation is
less than or equal to 0.3% of the mean, use the mean Cd in flow
equations as described in Sec. 1054.642, and use the CFV only down to
the lowest inlet pressure measured during calibration. If the standard
deviation exceeds 0.3% of the mean, omit the data point collected at
the lowest venturi inlet pressure. Recalculate the mean and standard
deviation and determine if the new standard deviation is less than or
equal to 0.3% of the new mean. If it is, then use that mean Cd in flow
calculations and use the CFV down to the lowest inlet pressure of the
remaining data points. If the standard deviation still exceeds 0.3% of
the mean, continue omitting the data point at the lowest inlet pressure
and recalculating the standard deviation and the mean. If the number of
remaining data points becomes less than seven, take corrective action.
For example, check for leaks or repeat the calibration process. If you
must repeat the process, we recommend applying tighter tolerances to
measurements and allow more time for flows to stabilize.
Sec. 1065.642 SSV, CFV, and PDP flow rate calculations.
(a) PDP flow rate. Based on the slopes and intercepts calculated in
Sec. 1065.640 for the speed that you operate your PDP during an
emission test, calculate flow rate, n as follows:
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Example:
fPDP = 755 rev/min
Pin = 98.575 kPa
R = 8.314472 J/(mol[middot]K)
Tin = 323.5 K
al = 50.43
ao = 0.056
Pout = 99.950 kPa
Cp = 1000 (J/m\3\)/kPa
ct = 60 s/min
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(b) SSV flow rate. Based on the Cd versus Re#
regression you determined as described in Sec. 1065.640, calculate SSV
flow rate, n during an emission test as follows:
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Example:
At = 0.01824 m2
Pin = 99.132 kPa
Z = 1
Mmix = 28.7805 g/mol
R = 8.314472 J/mol? K
Tin = 298.15 K
Re# = 7.232? 105
[gamma]
= 1.399
[beta]
= 0.8
[utri]p = 2.31 kPa
Cm = 1000 g/kg
Cp = 1000 Pa/kPa
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(c) CFV flow rate. Based on the mean Cd and other constants you
determined as described in Sec. 1065.640, calculate CFV flow rate,
[nacute]
during an emission test as follows:
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Example:
Cd = 0.985
CfCFV = 0.7219
At = 0.00456 m2
Pin = 98.836 kPa
Z = 1
Mmix = 28.7805 g/mol
R = 8.314472 J/mol? K
Tin = 378.15 K
[gamma]
= 1.399
[beta]
= 0.7
Cm = 1000 g/kg
Cp = 1000 Pa/kPa
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Sec. 1065.645 Amount of water in an ideal gas.
(a) For various emission calculations, you must calculate the
amount of water in an ideal gas, xH20.
(1) Based on the measured dewpoint, Tdew or frost point Tice and
the triple point of water, T0, use the formulations of the World
Meteorological Organization (General Meteorological Standards and
Recommended Practices, Appendix A, WMO Technical Regulations, WMO-No.
49, 2000, incorporated by reference at Sec. 1065.1010), to first
calculate the pressure of water, pH2O in an ideal gas as follows:
[[Page 54983]]
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Example:
Tdew = 9.5 [deg]C
Tdew = 9.5 + 273.15 = 282.65 K
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(2) And for frost point:
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Example:
Tice = -15.4 [deg]C
Tice = -15.4 + 273.15 = 275.75 K
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(3) The equation that uses dewpoint has been experimentally
confirmed from (0 to 100) [deg]C, and the same formula may be used over
super-cooled water from (-50 to 0) [deg]C with insignificant error. The
equation for frostpoint is valid from (-100 to 0) [deg]C.
(b) You may also use other formulas to convert dewpoint or
frostpoint to pH2O, provided that their use does not affect your
ability to show compliance with the applicable standards. Formulas such
as the commonly known the Goff-Gratch formula may be used. Note however
that the Wexler-Greenspan formula that we previously specified is not
valid for dewpoints below 0 [deg]C.
(c) To calculate the amount of water in an ideal gas, divide pH2O
by the absolute pressure (for example, barometric pressure) at which
you measured dewpoint or frostpoint, as follows:
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Example:
Psat = 1.186 kPa
Ptotal = 99.980 kPa
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Sec. 1065.650 Emission calculations.
(a) General. Calculate brake-specific emissions over each test
interval in a duty cycle. Refer to the standard-setting part for any
calculations you might need to determine a composite result, such as a
calculation that weights and sums the results of individual test
intervals in a duty cycle. We specify three ways to calculate brake-
specific emissions, as follows:
(1) Calculate the total mass of emissions and then divide it by the
total work generated over the test interval. In this section, we
describe how to calculate the total mass of different emissions. We
describe how to calculate total work. Divide the total mass by the
total work to determine brake-specific emissions, as follows:
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Example:
MNOx = 64.975 g
W = 25.783 kW[middot]hr
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eNOx = 2.520 g/(kW[middot]hr)
(2) For steady-state testing, you may calculate the ratio of
emission mass rate to power. In this special case you determine a mean
mass rate of emissions during steady-state operation, and then divide
that rate by the steady-state mean power. The result is a brake-
specific emission value calculated as follows:
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Example:
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P = 54.342 kW
Ct = 3600 s/hr
Cm = 1000 mg/g
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(3) Calculate the ratio of total mass to total work. This is a
special case in which you use a signal linearly proportional to raw
exhaust flow rate to determine a value proportional to total emissions.
You then use the same linearly proportional signal to determine total
work using a chemical balance of fuel, intake air and exhaust as
described in Sec. 1065.655, plus information about your engine's
brake-specific fuel consumption. In this case we do not require any
flow meter to be accurate, but we do require any flow meter you use
must meet the applicable linearity and repeatability specifications in
subpart D (performance checks) or subpart J (field testing) of this
part. The result is a brake-specific emission value calculated as
follows:
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Example:
m6co = 805.5 g
w6 = 52.102 kW[middot]hr
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(b) Total mass of emissions. To determine brake-specific emissions
for a test interval under paragraph (a)(1) of this section, calculate
the total mass of each emission. To calculate the total mass of an
emission, you multiply a concentration by its respective flow. Follow
these steps to calculate total mass of emissions:
(1) Concentration corrections and calculations. Before multiplying
concentrations by a flow, perform the following calculations on
recorded concentrations, in order, as follows:
(i) Correct all concentrations for drift, including dilution air
background concentrations. Correct for drift as described in Sec.
1065.657.
(ii) Optionally, correct all concentrations for instrument noise,
including dilution air background concentrations. Correct for noise as
described in Sec. 1065.658.
(iii) Correct all concentrations measured on a ``dry'' basis to a
``wet'' basis, including dilution air background concentrations.
Correct for drift as described in Sec. 1065.659.
(iv) Calculate all NMHC concentrations, including dilution air
background concentrations as described in Sec. 1065.660.
(v) If you performed an emission test with an oxygenated fuel (see
subpart E or this part) calculate any NMHCE concentrations including
dilution air background concentrations as described in Sec. 1065.665.
(2) Continuous sampling. For continuous sampling you frequently
record a continuously updated concentration signal. You may measure
this concentration from a changing flow rate or a constant flow rate,
as follows:
(i) If you continuously sample from a changing exhaust flow rate,
synchronously multiply it by the flow rate of the flow from which you
extracted it. We consider the following flows changing flows that
require a continuous multiplication of concentration times flow rate:
raw exhaust, exhaust diluted with a constant flow rate of dilution air,
and CVS dilution with a CVS flow meter that does not have an upstream
heat exchanger or electronic flow control. Account for dispersion and
time alignment as described in Sec. 1065.201. This multiplication
results in the flow rate of the emission itself. Integrate the emission
flow rate over a test interval to determine the total emission. If the
total emission is a molar quantity, convert this quantity to a mass by
multiplying it by its molar mass, M. The result is the mass of the
emission, m. The following is a continuous sampling with variable flow
example:
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Example:
MNMHC = 13.875389 g/mol
N = 1200
xNMHC1 = 84.5 [mu]mol/mol
xNMHC2 = 86.0 [mu]mol/mol
nexh1 = 2.876 mol/s
nexh2 = 2.224 mol/s
frecord = 1 Hz
Cmol = 1000000 [mu]ol/mol
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mNMHC = 13.875389 [middot]
(84.5 [middot]
2.876 +
86.0[middot]2.224 + ... + xNMHC1200 [middot]
nnexh1200 [middot]) [middot]
1 [middot]
1000000
mNMHC = 25.23 g
(ii) If you continuously sample from a constant exhaust flow rate,
you may calculate the mean concentration recorded over the test
interval and treat the mean as a batch sample (e.g., bag sample) as
described in paragraph (b)(3)(ii) of this section. We consider the
following flows constant exhaust flows: CVS diluted exhaust with a CVS
flow meter that has either an upstream heat exchanger, electronic flow
control, or both.
(3) Batch sampling. The concentration may also be a single
concentration from a proportionally extracted batch sample (e.g., a
bag). In this case, you multiply the mean concentration of the batch
sample by the total flow from which the sample was extracted. You may
calculate total flow by integrating a changing flow rate or by
determining the mean of a constant flow rate, as follows:
(i) If you batch sample from a changing exhaust flow rate, extract
a sample proportional to the changing exhaust flow rate. We consider
the following flows changing flows that require proportional sampling:
raw exhaust, exhaust diluted with a constant flow rate of dilution air,
and CVS dilution with a CVS flow meter that does not have an upstream
heat exchanger or electronic flow control. Integrate the flow rate over
a test interval to determine the total flow from which you extracted
the proportional sample. Multiply the mean concentration of the batch
sample by the total flow from which the sample was extracted. If the
total emission is a molar quantity, convert this quantity to a mass by
multiplying it by its molar mass. If the total emission is a molar
quantity, convert this quantity to a mass by multiplying it by its
molar mass, M. The result is the mass of the emission, m. In the case
of PM emissions, where the mean PM concentration is already in units of
mass per mole of sample, MPM, simply multiply the total flow
by MPM. The result is the total mass of PM,mPM.
[[Page 54985]]
The following is a batch sample extracted from a variable flow rate
example:
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Example:
MNOx = 46.0055 g/mol
N=9000
xNOx = 85.6 [mu]mol/mol
ndexh1 = 25.534 mol/s
ndexh2 = 26.950 mol/s
frecord = 5 Hz
Cmol = 1000000 [mu]mol/mol
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mNOx = 46.0055 [middot]
85.6(25.534 + 26.950 + ... +
ndexh9000) [middot]
0.2 [middot]
1000000
mNOx = 4.201 g
(ii) If you batch sample from a constant exhaust flow rate, extract
a sample at a constant flow rate. We consider the following flows
constant exhaust flows: CVS diluted exhaust with a CVS flow meter that
has either an upstream heat exchanger, electronic flow control, or
both. Determine the mean flow rate from which you extracted the
constant flow rate sample. Multiply the mean concentration of the batch
sample by the mean flow rate of the exhaust from which the sample was
extracted, and multiply the result by the time of the test interval. If
the total emission is a molar quantity, convert this quantity to a mass
by multiplying it by its molar mass, M. The result is the mass of the
emission, m. In the case of PM emissions, where the mean PM
concentration is already in units of mass per mole of sample,
MPM, simply multiply the total flow by MPM. The
result is the total mass of PM,mPM.
(iii) The following is a batch sample extracted from a constant
flow rate example:
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Example:
M PM = 0.144 mg/mol
ndexh = 57.692 mol/s
[Delta]t = 20 min
Ct = 60 s/min
Cm = 1000 mg/g
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(4) Diluted exhaust sampling; continuous or batch. If you sampled
emissions from diluted exhaust, you must consider two additional steps.
(i) If you diluted a sample at a constant ratio of dilution air
flow rate to exhaust flow rate (raw or dilute), you must multiply your
total mass emissions by the sum of the dilution ratio, DR, plus one.
The following is an example of a secondary dilution system for sampling
PM from a CVS:
mPM = mPMdil? (DR+1)
Example:
mPMdil = 6.853 g
DR = 5:1
mPM = 6.853? (5+1)
mPM = 41.118 g
(ii) You may optionally measure background emissions in dilution
air by either continuous sampling or batch sampling. You may then
subtract the background you would have otherwise attributed to your
engine as described in Sec. 1065.667.
(5) NOX correction for intake-air humidity. Correct the
total mass of NOX based on intake-air humidity as described
in Sec. 1065.670. Note that if you performed diluted exhaust sampling,
perform this correction after correcting for any dilution air
background.
(c) Total work. To determine brake-specific emissions for a test
interval as described in paragraph (a)(1) of this section, you must
also calculate the total work. To calculate total work, multiply the
feedback engine speed by its respective feedback torque and apply the
appropriate units conversion factors. This results in the power of the
engine. Integrate the power over a test interval to determine the total
work. If your standard is in the units g/hp.hr use the following
conversion factor: 1 hp =550 ft lbf/s = 0.77456999 kW, and round the
resulting value. The following is an example:
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Example:
N = 9000
fn1 = 1800.2 rev/min
fn2 = 1805.8 rev/min
T1 = 177.23 N? m
T2 = 175.00 N? m
Crev = 2? [pgr]
rad/rev
Ct1 = 60 s/min
Cp = 1000 (N? m/s)/kW
frecord = 5 Hz
Ct2 = 3600 s/hr
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(d) Steady-state mass rate divided by power. To determine steady-
state brake-specific emissions for a test interval as described in
paragraph (a)(2) of this section, calculate the steady-state mass rate
of the emission. Then calculate the steady-state power. Divide the mean
mass rate of the emission by the mean power to determine steady-state
brake-specific emissions.
(1) To calculate the mass rate of an emission, multiply its mean
concentration (e.g., x) by its respective mean flow rate,
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If the result is a molar flow rate, convert this quantity to a mass
rate by multiplying it by its molar mass, M. The result is the mean
mass rate of the emission,
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In the case of PM emissions, where the mean PM concentration is already
in units of mass per mole of sample, M PM, simply multiply
the mean flow rate,
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by MPM. The result is the mass rate of PM,
PM.
(2) To calculate power, multiply mean engine speed, fn,
by its respective mean torque, T, and apply the appropriate units
conversion factors. The results is the mean power of the engine, P.
[[Page 54986]]
(3) Divide emission mass rate by power to calculate a brake-
specific emission result as described in paragraph (a)(2) of this
section.
(4) The following is an example of how to calculate mean mass rate
and mean power:
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P=fn[middot]T
Examples:
MCO=28.0101 g/mol
xCO=12.00 mmol/mol
n=1.530 mol/s
Cmol=1000 mmol/mol
f=3584.5 rev/min
T=121.50 N[middot]m
Crev=2[middot][pi]
rad/rev
Ct=60 s/min
Cp=1000 (N[middot]m/s)/kW
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(e) Ratio of total mass of emissions to total work. To determine
brake-specific emissions for a test interval as described in paragraph
(a)(3) of this section, calculate a value proportional to the total
mass of each emission. Divide each proportional value by a value that
is similarly proportional to total work. The result is a brake-specific
emission.
(1) Total mass. To determine a value proportional to the total mass
of an emission, determine total mass as described in paragraph (b) of
this section, except substitute for the flow rate, n, or the total
flow, n with a signal that is linearly proportional to flow rate,
or linearly proportional to total flow, [ntilde].
(2) Total work. To calculate a value proportional to total work
over a test interval, integrate a value that is proportional to power.
Use information about the brake-specific fuel consumption of your
engine, efuel to convert a signal proportional to fuel flow
rate to a signal proportional to power. To determine a signal
proportional to fuel flow rate, divide a signal that is proportional to
the mass rate of carbon products by the fraction of carbon in your
fuel, wc.. For your fuel, you may use a measured
wc or you may use the default values in Table 1 of Sec.
1065.655. Calculate the mass rate of carbon from the amount of carbon
and water in the exhaust, which you determine with a chemical balance
of fuel, intake air, and exhaust as described in Sec. 1065.655. In the
chemical balance, you must use concentrations from the flow that
generated the signal proportional to flow rate, [ntilde], in paragraph
(e)(1) of this section. The following is an example of how to determine
a signal proportional to total work over a test interval:
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Example:
N = 3000
frecord = 5 HZ
efuel = 285 g/(kW[middot]hr
wfuel = 0.869 g/g
Mc = 12.0107 g/mol
n1 = 3.922 mol/s
xCproddry1 = 91.634 mmol/mol
xH2O1 = 26.16 mmol/mol
n2 = 4.139 mol/s
xCproddry2 = 98.005 mmol/mol
xH2O2 = 27.21 mmol/mol
Cmol = 1000 mmol/mol
Ct s/hr
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(3) Use the value proportional to total mass and the value
proportional to total work to determine brake-specific emissions as
described in paragraph (a)(3) of this section.
(f) Rounding. Round emission values only after all calculations are
complete and the result is in g/kW[middot]hr or units equivalent to the
units of the standard (i.e., g/hp[middot]hr.).
(1) General. To replace a number having a given number of digits
with a number having a smaller number of digits, follow these rules:
(i) If the digits to be discarded begin with a digit less than 5,
the digit preceding the 5 is not changed. Example : 6.9749515 rounded
to 3 digits is 6.97.
(ii) If the digits to be discarded begin with a 5 and at least one
of the following digits is greater than 0, the digit preceding the 5 is
increased by 1. Examples : 6.9749515 rounded to 2 digits is 7.0,
6.9749515 rounded to 5 digits is 6.9750.
(iii) If the digits to be discarded begin with a 5 and all of the
following digits are 0, the digit preceding the 5 is unchanged if it is
even and increased by 1 if it is odd. (Note that this means that the
final digit is always even.) Examples : 6.9749515 rounded to 7 digits
is 6.974952, 6.974950 5 rounded to 7 digits is 6.974950.
(2) Rounding converted numerical values. In most cases the product
of the unconverted numerical value and a conversion factor will be a
numerical value with a number of digits that exceeds the number of
significant digits of the unconverted numerical value. Proper
conversion procedure requires rounding this converted numerical value
to the number of significant digits that is consistent with the maximum
possible rounding error of the unconverted numerical value. Example :
To express the value 1 = 36 ft in meters, use the factor 0.3048 and
write 1 = 36 ft 3 0.3048 m/ft = 10.9728 m = 11.0 m. The final result, 1
= 11.0 m, is based on the following reasoning: The numerical value
``36'' has two significant digits, and thus a relative maximum possible
rounding error (abbreviated RE) of 0.5/36 = 1.4% because it could have
resulted from rounding the number 35.5, 36.5, or any number between
35.5 and 36.5. To be consistent with this RE, the converted numerical
value ``10.9728'' is rounded to 11.0 or three significant digits
[[Page 54987]]
because the number 11.0 has an RE of 0.05/11.0 = 0.45%. Although this
0.45% RE is one-third of the 1.4% RE of the unconverted numerical value
``36,'' if the converted numerical value ``10.9728'' had been rounded
to 11 or two significant digits, information contained in the
unconverted numerical value ``36'' would have been lost. This is
because the RE of the numerical value ``11'' is 0.5/11 = 4.5%, which is
three times the 1.4% RE of the unconverted numerical value ``36.'' This
example therefore shows that when selecting the number of digits to
retain in the numerical value of a converted quantity, one must often
choose between discarding information or providing unwarranted
information. Consideration of the end use of the converted value can
often help one decide which choice to make. Note: Consider that one had
been told initially that the value 1 = 36 ft had been rounded to the
nearest inch. Then in this case, since 1 is known to within 1 in, the
RE of the numerical value ``36'' is 1 in/(36 ft 3 12 in/ft) = 0.23%.
Although this is less than the 0.45% RE of the number 11.0, it is
comparable to it. Therefore, the result 1 = 11.0 m is still given as
the converted value. Note that the numerical value ``10.97'' would give
excessive unwarranted information because it has an RE that is one-
fifth of 0.23%.
Sec. 1065.655 Chemical balances of fuel, intake air, and exhaust.
(a) General. Chemical balances of fuel, intake air, and exhaust may
be used to calculate ratios of their flows, the amount of water in
their flows, and the concentration of constituents in their flows.
Along with the flow rate of either fuel, intake air, or exhaust you may
use chemical balances to determine the flows of the other two. For
example, you may use chemical balances along with exhaust flow to
determine fuel flow and intake flow.
(b) Procedures that require chemical balances. We require chemical
balances when you determine the following:
(1) A value proportional to total work, W6, when you choose to
determine brake-specific emissions as described in Sec. 1065.650(e).
(2) The amount of water in a raw or diluted exhaust flow,
xH2On, when you do not measure the amount of water in a flow
to correct for the amount water removed, as described in Sec.
1065.659(c)(2).
(3) The flow-weighted average fraction of dilution air in diluted
exhaust, DF, when you do not measure dilution air flow to correct for
background emissions as described inSec. 1065.667(c).
(c) Chemical balance procedure. The calculations for a chemical
balance involve a system of equations that require iteration. We
recommend using a computer to solve this system of equations. You must
guess the initial values of up to three quantities: the amount of water
in the measured flow, xH2O, fraction of dilution air in
diluted exhaust, DF, and the amount of products on a C1
basis per dry mole of dry measured flow, xCproddry. For each
emissions concentration, x, and amount of water xH2O, you
must determine their completely dry concentrations. xdry and
xH2Odry. You must also use your fuel's atomic hydrogen to
carbon ratio, [alpha], and oxygen to carbon ratio, [beta]. For your
fuel, you may measure [alpha]
and [beta]
or you may use the default
values in Table 1 of Sec. 1065.650. Use the following steps to
complete a chemical balance:
(1) Convert your measured concentrations such as,
xCO2meas, xNOmeas, and xH2Oint, to dry
concentrations by dividing them by one minus the amount of water
present during their respective measurements: xH2OxCO2,
xH2OxNO, and xH2Oint. If the amount of water
present during a ``wet'' measurement is the same as the unknown amount
of water in the exhaust flow, xH2O, iteratively solve for
that value in the system of equations. If you measure only total
NOX and not NO and NO2 separately, use good
engineering judgement to split your total NOX between NO and
NO2 for the chemical balances. For example, if you measure
emissions from a stoichiometric spark-ignition engine, you may assume
all NOX is NO. For a compression-ignition engine, you may
assume NOX is 75% NO and 25% NO2. For
NO2 storage aftertreatment systems, you may assume
NOX is 75% NO2 and 25% NO. Note that for
emissions calculations you must use the molar mass of NO2
for the molar mass of all NOX, regardless of the actual
NO2 fraction of NOX.
(2) Enter the equations in paragraph (c)(3) of this section into a
computer program to iteratively solve for xH2O and
xCproddry. If you measure raw exhaust flow, set DF equal to
zero (0). If you measure diluted exhaust flow, iteratively solve for
DF. Use good engineering judgment to guess initial values for
xH2O, xCproddry, and DF. We recommend guessing an
initial amount of water that is about twice the amount of water in your
intake or dilution air. We recommend guessing an initial value of
xCproddry as the sum of your measured CO2, CO,
and THC values. If you measure diluted exhaust, we also recommend
guessing an initial DF between 0.75 and 0.95, such as 0.8. Perform
iteration until the most recently updated guesses are all within < plus-
minus>1% of their respective most recently calculated values.
(3) In the equations that follow, we use the following symbols and
subscripts:
xH20 = amount of water in measured flow
xH20dry = amount of water per dry mole of measured flow
xCproddry = amount of carbon products on a C1 basis per dry mole of
measured flow
DF = fraction of dilution air in measured flow--assuming stoichiometric
exhaust
xprod/intdry = amount of dry stoichiometric products per dry mole of
intake air
x02proddry = amount of oxygen products on an O2 basis per dry mole of
measured flow
x[emission]dry = amount of emission per dry mole of measured flow
x[emission]meas = amount of emission in measured flow
xH20[emission]meas = amount of water at emission measurement location
xH20int = amount of water in intake air
xH20dil = amount of water in dilution air
x02airdry = amount of oxygen per dry mole of air; 0.209445 mol/mol
x02airdry = amount of carbon dioxide per dry mole air; 375 [mu]mol/mol
[alpha]
= atomic hydrogen to carbon ratio in fuel
[beta]
= oxygen to carbon ratio in fuel
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(4) The following is an example; iteratively solved using the
equations in paragraph (c)(3) of this section:
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Table 1 of Sec. 1065.655.--Default Values of Atomic Hydrogen to Carbon
Ratio, [alpha], Atomic Oxygen to Carbon Ratio, [beta], and Carbon Mass
Fraction of Fuel, wC, for Various Fuels
------------------------------------------------------------------------
Atomic hydrogen and
oxygen to carbon Carbon mass
Fuel ratios concentration,
CH[alpha]O[beta]
wc g/g
------------------------------------------------------------------------
Gasoline......................... CH1.85O0 0.866
#2 Diesel................ CH1.80O0 0.869
#1 Diesel................ CH1.93O0 0.861
LPG (C3H8)....................... CH2.67O0 0.817
LNG/CNG.......................... CH3.79O0.02 0.707
Ethanol.......................... CH3O0.5 0.521
Methanol......................... CH4O1 0.375
------------------------------------------------------------------------
Sec. 1065.657 Drift validation and correction.
(a) Determine if measurement instrument drift invalidates a test.
Use the following quantities and calculation to determine if drift
invalidates a test:
(1) Span reference, xref.
(2) Post-test span check, xspanchk.
(3) Post-test zero check, xzerochk.
(4) Flow-weighted amount expected at either the standard or during
a test interval, whichever is greater, xexp.
(5) Calculate drift correction, as follows:
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Example:
xspanchk = 1695.8 [mu]mol/mol
xzerochk = -5.2 [mu]mol/mol
xref = 1800.0 [mu]mol/mol
xexp = 435.5 [mu]mol/mol
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(b) You may correct every recorded amount for drift if drift did
not invalidate the test. Use the following quantities and calculation
to correct for drift:
(1) The quantities from paragraph (a) of this section.
(2) Each recorded amount, xi or for batch sampling, [xmacr].
(3) Correct for drift as follows:
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Example:
xspanchk = 1695.8 [mu]mol/mol
xzerochk = -5.2 [mu]mol/mol
xref = 1800.0 [mu]mol/mol
xi or x = 435.5 [mu]mol/mol
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Sec. 1065.658 Noise correction.
(a) You may set to zero any recorded data point if that point's
numerical value is smaller than the least of the following values:
(1) The measurement instrument noise determined according to Sec.
1065.305.
(2) For lab instruments the recommended noise limit specified in
Table 1 of Sec. 1065.205.
(3) For field-testing instruments, the recommended noise limit
specified in Table 1 of Sec. 1065.915.
(b) If you perform this noise correction on samples that are
corrected for background concentrations in dilution air, then noise
correct the respective dilution air measurements the same way.
(c) If you perform this noise correction on a THC concentration
that you use to determine NMHC, then correct the CH4
concentration the same way.
Sec. 1065.659 Removed water correction.
(a) If you remove water upstream of a concentration measurement, x,
or upstream of a flow measurement, n, correct for the removed water.
Perform this correction based on the amount of water at the
concentration measurement, xH2O[emission]meas, and at the flow meter,
xH2O, whose flow is used to determine the concentration's total mass
over a test interval.
(b) Downstream of where you removed water, you may determine the
amount of water remaining by any of the following:
(1) Measure the dewpoint temperature and absolute pressure
downstream of the water removal location and then calculate the amount
of water remaining as described in Sec. 1065.645.
(2) If you can justify assuming saturated water vapor conditions at
a given location, you may use the measured temperature at that location
as the dewpoint temperature.
(3) You may also use a nominal value of absolute pressure based on
an alarm setpoint, a pressure regulator setpoint, or good engineering
judgment.
(c) For a corresponding concentration or flow measurement where you
did not remove water, you may determine the amount of initial water by
any of the following:
(1) Use any of the techniques described in paragraph (b) of this
section.
(2) If the measurement is a raw exhaust measurement, you may
determine the amount of water based on intake-air humidity, plus a
chemical balance of fuel, intake air and exhaust as described in Sec.
1065.655.
(3) If the measurement is a diluted exhaust measurement, you may
determine the amount of water based on intake-air humidity, dilution
air humidity, and a chemical balance of fuel, intake air and exhaust as
described in Sec. 1065.655.
(d) Perform a removed water correction to the concentration
measurement using the following calculation:
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Example:
\X\COmeas = 29.0 [mu]mol/mol
\X\H2OCOmeas = 8.601 [mu]mol/mol
\X\H20 = 34.4 [mu]mol/mol
\C\mol = 1000 [mu]mol/mol
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Sec. 1065.660 THC and NMHC determination.
(a) THC determination. If we require you to determine THC emission,
calculate \x\THC using the initial THC contamination
concentration \x\THCinit from Sec. 1065.520 as follows:
\X\THC = \X\THCinit
Example:
\X\THC = 150.3 [mu]mol/mol
\X\THCinit = 1.1 [mu]mol/mol
\X\THC = 150.3 - 1.1
\X\THC = 149.2 [mu]mol/mol
(b) NMHC determination. Use one of the following to determine NMHC
emission, \X\NMHC
(1) If you did not measure CH4, you may report
\X\NMHC as 0.98.\X\THC.
(2) For nonmethane cutters, calculate \X\NMHC using the
nonmethane cutter's penetration fractions (PF) of CH4, and
C2H6, from Sec. 1065.331, and using the initial
NMHC contamination concentration \X\NMHCinit from Sec.
1065.520 as follows:
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Example:
\X\THC = 150.3 [mu]mol/mol
\X\CH4 = 20.5 [mu]mol/mol
\PF\CH4 = 0.980
\PF\C2H6 = 0.050
\X\NMHCinit = 1.1 [mu]mol/mol
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(3) For a gas chromatograph, calculate \X\NMHC using the
THC analyzer's response factor (RF) CH4, from Sec.
1065.366, and using the initial NMHC contamination concentration
\X\NMHCinit from Sec. 1065.520 as follows:
\X\NMHC = \X\THC-
\RF\CH4[middot]\X\CH4-\X\NMHCinit
Example:
\X\THC = 145.6 [mu]mol/mol
\X\CH4 = 18.9 [mu]mol/mol
\RF\CH4 = 0.970
\X\NMHCinit = 1.1 [mu]mol/mol
\X\NMHC = 145.6-0.970[middot]18.9-1.1
\X\NMHC = 126.2 [mu]mol/mol
(4) If the result of paragraph (b)(2) or (3) of this section is
greater than the result of paragraph (b)(1) of this section, use the
value calculated under paragraph (b)(1) of this section.
Sec. 1065.665 THCE and NMHCE determination.
(a) If we require you to determine THCE, consider references to
NMHC and NMHCE in this section to mean THC and THCE, respectively. If
we require you to determine NMHCE, first determine NMHC as described in
Sec. 1065.660.
(b) If you measured an oxygenated hydrocarbon's mass concentration
(per mole of exhaust), then first calculate its molar concentration by
dividing its mass concentration by the molar mass of the oxygenated
hydrocarbon.
(c) Then multiply each oxygenated hydrocarbon's molar concentration
by its respective number of carbon atoms per molecule. Add these
carbon-equivalent molar concentrations to the molar concentration of
NMHC. The result is the molar concentration of NMHCE.
(d) For example, if you measured ethanol
(C2H5OH) and methanol (CH3OH) as molar
concentrations, and acetaldehyde (C2H4O) and
formaldehyde (HCHO) as mass concentrations, you
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would determine NMHCE emissions as follows:
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Example:
xNMHC = 127.3 [mu]mol/mol
xC2H5OH = 100.8 [mu]mol/mol
xCH3OH = 25.5 [mu]mol/mol
MexhC2H4O = 0.841 mg/mol
MexhHCHO = 39.0 [mu]g/mol
MC2H4O = 44.05256 g/mol
MHCHO = 30.02598 g/mol
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Sec. 1065.667 Dilution air background emission correction.
(a) General. To determine the mass of background emissions to
subtract from a diluted exhaust sample, first determine the total flow
of dilution air, ndil, over the test interval. This may be a measured
quantity or a quantity calculated from the diluted exhaust flow and the
flow-weighted average fraction of dilution air in diluted exhaust, DF.
Multiply the total flow of dilution air by the mean concentration of a
background emission, xdil. This may a time-weighted mean or
a flow-weighted mean (e.g. a proportionally sampled background). The
product of ndil and xdil is the total amount of a background
emission. If this is a molar quantity, convert it to a mass by
multiplying it by its molar mass, M. The result is the mass of the
background emission, m. In the case of PM, where the mean PM
concentration is already in units of mass per mole of sample, MPM,
simply multiply the total amount of dilution air by MPM. The result is
the total background mass of PM, mPM. Subtract the total background
mass from the total mass to correct for background emissions.
(b) You may determine the total flow of dilution air by a direct
flow measurement. In this case calculate the total mass of background
as described in Sec. 1065.650(b), using the dilution air flow,
ndil. Subtract the background mass from the total mass. Use
the result in brake-specific emissions calculations.
(c) You may determine the total flow of dilution air from the total
flow of diluted exhaust and a chemical balance of the fuel, intake air
and exhaust as described in Sec. 1065.655. In this case calculate the
total mass of background as described in Sec. 1065.650(b), using the
total flow of diluted exhaust, ndexh. Then multiply this result by the
flow-weighted average fraction of dilution air in diluted exhaust, DF.
Calculate DF using flow-weighted average concentrations of emissions in
the chemical balance, as described in Sec. 1065.655. You may assume
that your engine operates stoichiometrically, even if it is a lean-burn
engine, such as a compression-ignition engine. Note that for lean-burn
engines this assumption could result in an error in emissions
calculations. This error could occur because the chemical balances in
Sec. 1065.655 correct excess air passing through a lean-burn engine as
if it was dilution air. If an emission concentration expected at the
standard is about 100 times its dilution air background concentration,
this error is negligible. However, if an emission concentration
expected at the standard is similar to its background concentration,
this error could be significant. If you are concerned about this error,
we recommend that you remove background emissions from dilution air by
HEPA filtration, chemical adsorption, or catalytic scrubbing. You might
also consider using a partial-flow dilution technique such as a bag
mini-diluter, which uses purified air as the dilution air.
(d) The following is an example of using the flow-weighted average
fraction of dilution air in diluted exhaust, DF. and the total mass of
background emissions calculated using the total flow of diluted
exhaust, ndexh, as described in Sec. 1065.650(b):
Mbkgnd = df[middot]Mbkgnddexh
Mbkgnddexh = M[middot]xbkgnd[middot]ndexh
Example:
MNOx = 46.0055 g/mol
xbkgnd = 0.05 [mu]mol/mol
ndexh = 23280.5 mol
DF = 0.843
Cmol = 1000000 [mu]mol/mol
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Sec. 1065.670 NOX intake-air humidity correction.
(a) Correct NOX concentrations for intake-air humidity
after applying all other corrections.
(b) For compression-ignition engines correct for intake-air
humidity as follows or develop your own correction, based on good
engineering judgment:
XNOcorr = XNOxuncorr [middot](9.953[middot]
XH20 + 0.832)
Example:
XNOxuncorr = 700.5 [mu]mol/mol
XH20 = 0.022 mol/mol
XNOxcorr = 700.5[middot](9.953[middot]0.022 + 0.832)
XNOxcorr = 736.2 [mu]mol/mol
(c) For spark-ignition engines you may use the same correction as
for compression-ignition engines, or you
[[Page 54992]]
may develop your own correction, based on good engineering judgment.
Sec. 1065.672 CLD quench check calculations.
Perform CLD quench check calculations as follows:
(a) Calculate the amount of water in the span gas,
xH2Ospan assuming complete saturation at the span gas
temperature.
(b) Estimate the expected amount of water, xH2Oexp in
the exhaust you sample by considering the maximum expected amounts of
water in combustion air, in fuel combustion products, and in dilution
air if you dilute.
(c) Calculate water quench as follows:
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Example:
XNOdry = 1800 [mu]mol/mol
XNOwet = 1760 [mu]mol/mol
XH20exp = 0.03 mol/mol
XH20calc = 0.017 mol/mol
XNO,CO2 = 1480 [mu]mol/mol
XNO,N2 = 1500 [mu]mol/mol
XCO2exp = 2.0%
XCO2meas = 3.0%
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Sec. 1065.690 PM sample media buoyancy correction.
(a) General. Correct PM sample media for their buoyancy in air if
you weigh them on a balance. The buoyancy correction depends on the
sample media density, the density of air, and the density of the
calibration weight used to calibrate the balance. The buoyancy
correction does not account for the buoyancy of the PM itself because
the mass of PM typically accounts only for (0.01 to 0.10)% of the total
weight. A correction to this small fraction of mass would be at the
most (0.001 to 0.010)%.
(b) PM sample media density. Different PM sample media have
different densities. Use the known density of your sample media, or use
one of the densities for some common sampling media:
(1) For PTFE coated borosilicate glass, use a sample media density:
2300 kg/m\3\.
(2) For PTFE membrane (film) media with an integral support ring of
polymethylpentene that accounts for 95% of the media mass, use a sample
media density: 920 kg/m\3\.
(c) Air density. Because a PM balance environment must be tightly
controlled to an ambient temperature of (22 ±1) [deg]C and a
dewpoint of (9.5 ±1) [deg]C, air density is only a function
of barometric pressure for this correction.
(d) Calibration weight density. Use the stated density of the
material of your metal calibration weight. The example calculation in
this section uses a density of 8000 kg/m\3\, but you should know the
density of your weight from the calibration weight supplier or the
balance manufacturer if it is an internal weight.
(e) Correction calculation. Buoyancy correct PM sample media using
the following:
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Example:
muncorr = 100.0000 mg
[rho]barom = 101.325 kPa
[rho]weight = 8000 kg/m\3\
[rho]media = 920 kg/m\3\
[rho]air = (1.1803[middot]10-\2\[middot]101.325)-
5.2922[middot]10-\3\
[rho]air = 1.1906 kg/m\3\
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TP10SE04.172
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TP10SE04.173
Sec. 1065.695 Data requirements.
(a) To determine the information we require from engine tests,
refer to the standard-setting part and request from your Designated
Compliance Officer the application format for certification. We may
require different information for different purposes such as for
certification applications, alternate procedure approval requests,
selective enforcement audits, laboratory audits, production-line test
reports, and field-test reports.
(b) See the standard-setting part and Sec. 1065.25 regarding
recordkeeping.
(c) We may ask you the following about your testing:
(1) What approved alternative procedures did you use? For example:
(i) Partial-flow dilution for proportional PM.
(ii) CARB test procedures.
(iii) ISO test procedures.
(2) What laboratory equipment did you use? For example, the make,
model, and description of the following:
(i) Engine dynamometer and operator demand.
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(ii) Probes, dilution, transfer lines, and sample preconditioning
components.
(iii) Batch storage media (e.g., bag material, PM filter material).
(3) What measurement instruments did you use? For example, the
make, model, and description of the following:
(i) Speed, torque instruments.
(ii) Flow meters.
(iii) Gas analyzers.
(iv) PM balance.
(4) When did you conduct calibrations and performance checks and
what were the results? For example, the dates and results of the
following:
(i) Linearity checks.
(ii) Interference checks.
(iii) Response checks.
(iv) Leak checks.
(v) Flow meter checks.
(5) What engine did you test? For example, the following:
(i) Manufacturer.
(ii) Family name on engine label.
(iii) Model.
(iv) Model year.
(v) Identification number.
(6) How did you prepare and configure your engine for testing? For
example, the following:
(i) Service accumulation; dates, hours, duty cycle and fuel.
(ii) Scheduled maintenance; dates and description.
(iii) Unscheduled maintenance; dates and description.
(iv) Intake restriction allowable pressure range.
(v) Charge air cooler volume.
(vi) Charge air cooler outlet temperature, specified engine
conditions and location of temperature measurement.
(vii) Exhaust restriction allowable pressure range.
(viii) Fuel temperature and location of measurement.
(ix) Any aftertreatment system configuration and description.
(x) Any crankcase ventilation configuration and description (e.g.,
open, closed, PCV, crankcase scavenged).
(7) How did you test your engine? For example:
(i) Constant speed or variable speed.
(ii) Mapping procedure: step or sweep.
(iii) Continuous or batch sampling for each emission.
(iv) Raw or dilute; any dilution air background sampling.
(v) Duty cycle and test intervals.
(vi) Cold-start, hot-start, warmed-up running.
(vii) Intake and dilution air absolute pressure, temperature,
dewpoint.
(viii) Simulated engine loads, curb idle transmission torque value.
(ix) Warm idle speed value, any enhanced idle speed value.
(x) Simulated vehicle signals applied during testing.
(xi) Bypassed governor controls during testing.
(xii) Date, time, and location of test (e.g., dynamometer
laboratory identification).
(xiii) Cooling medium for engine and charge air.
(xiv) Operating temperatures: coolant, head, block.
(xv) Full names of engine operators and laboratory operators.
(xvi) Natural or forced cool-down and cool-down time.
(xvii) Cannister loading.
(8) How did you validate your testing? For example, results from
the following:
(i) Duty cycle regression statistics for each test interval.
(ii) Proportional sampling.
(iii) Drift.
(iv) Reference PM sample media in PM-stabilization environment.
(9) How did you calculate results? For example, results from the
following:
(i) Drift correction.
(ii) Noise correction.
(iii) ``Dry-to-wet'' correction.
(iv) NMHC CH4 and contamination correction.
(v) NOx humidity correction.
(vi) Brake-specific emission formulation: total mass divided by
total work, mass rate divided by power, or ratio of mass to work.
(vii) Rounding emission results.
(10) What were the results of your testing? For example:
(i) Maximum mapped power and speed at maximum power.
(ii) Maximum mapped torque and speed at maximum torque.
(iii) For constant-speed engines: no-load governed speed.
(iv) For constant-speed engines: test torque.
(v) For variable-speed engines: test speed.
(vi) Speed versus torque map.
(vii) Speed versus power map.
(viii) Duty cycle and test interval brake-specific emissions.
(ix) Brake-specific fuel consumption.
(11) What fuel did you use? For example:
(i) Fuel that met specifications of subpart H of this part.
(ii) Alternative fuel.
(iii) Oxygenated fuel.
(12) How did you field test your engine? For example:
(i) Data from paragraphs (c)(1), (3), (4), (5), and (9) of this
section.
(ii) Probes, dilution, transfer lines, and sample preconditioning
components.
(iii) Batch storage media (e.g., bag material, PM filter material).
(iv) Continuous or batch sampling for each emission.
(v) Raw or dilute; any dilution air background sampling.
(vi) Cold-start, hot-start, warmed-up running.
(vii) Intake and dilution air absolute pressure, temperature,
dewpoint.
(viii) Curb idle transmission torque value.
(ix) Warm idle speed value, any enhanced idle speed value.
(x) Date, time, and location of test (e.g., dynamometer laboratory
identification).
(xi) Proportional sampling validation.
(xii) Drift validation.
(xiii) Operating temperatures: coolant, head, block.
(xiv) Full name of vehicle operator.
(xv) Full names of field test operators.
(xvi) Vehicle make, model, model year, identification number.
Subpart H--Engine Fluids, Test Fuels, and Analytical Gases
Sec. 1065.701 General requirements for test fuels.
(a) For all emission tests, use test fuels meeting the
specifications in this subpart unless the standard-setting part directs
otherwise. If we do not specify a service-accumulation fuel for a test
engine, use a fuel typical of what you would expect the engine to use
in service.
(b) If you produce engines that can run on a type of fuel (or
mixture of fuels) that we do not specify in this subpart, you must get
our approval to test with fuel representing commercially available
fuels of that type. We must approve your fuel specifications before you
start testing.
(c) You may use a test fuel other than those we specify in this
subpart if you do all the following:
(1) Show that it is commercially available.
(2) Show that your engines will use only the designated fuel in
service.
(3) Show that operating the engines on the fuel we specify would
increase emissions or decrease durability.
(4) Get our written approval before you start testing.
(d) We may allow you to use a different test fuel (such as
California Phase 2 gasoline) if you show us that using it does not
affect your ability to comply with all applicable emission standards.
Sec. 1065.703 Distillate diesel fuel.
(a) Distillate diesel fuels for testing must be clean and bright,
with pour and
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cloud points adequate for proper engine operation.
(b) There are three grades of #2 diesel fuel specified for
use as a test fuel. See the standard-setting part to determine which
grade to use. If the standard-setting part does not specify which grade
to use, use good engineering judgment to select the grade that
represents the fuel on which the engines will operate in use. The three
grades are specified in Table 1 of this section.
(c) You may use the following nonmetallic additives with distillate
diesel fuels:
(1) Cetane improver.
(2) Metal deactivator.
(3) Antioxidant, dehazer.
(4) Rust inhibitor.
(5) Pour depressant.
(6) Dye.
(7) Dispersant.
(8) Biocide.
Table 1 of Sec. 1065.703.--Test Fuel Specifications for Distillate Diesel Fuel
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Ultra low Low
Item Units sulfur sulfur High sulfur Reference procedure \1\
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Cetane Number -- 40-50 40-50 40-50 ASTM D 613-03b
----------------------------
Distillation range:
Initial boiling point ..................... 171-204 171-204 171-204 .........................
10 pct. point ..................... 204-238 204-238 204-238 .........................
50 pct. point [deg]C 243-282 243-282 243-282 ASTM D 86-03.
90 pct. point ..................... 293-332 293-332 293-332 .........................
Endpoint ..................... 321-366 321-366 321-366 .........................
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Gravity [deg]API 32-37 32-37 32-37 ASTM D 287-92.
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Total sulfur mg/kg 7-15 300-500 2000-4000 ASTM D 2622-03.
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Aromatics, minimum. g/kg 100 100 100 ASTM D 5186-03.
(Remainder shall be
paraffins, naphthalenes,
and olefins)
----------------------------
Flashpoint, min. [deg]C 54 54 54 ASTM D 93-02a.
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Viscosity cSt 2.0-3.2 2.0-3.2 2.0-3.2 ASTM D 445-03.
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\1\ All ASTM standards are incorporated by reference in Sec. 1065.1010.
Sec. 1065.705 Residual fuel. [Reserved]
Sec. 1065.710 Gasoline.
(a) Gasoline for testing must have octane values that represent
commercially available fuels for the appropriate application.
(b) There are two grades of gasoline specified for use as a test
fuel. If the standard-setting part requires testing with fuel
appropriate for low temperatures, use the test fuel specified for low-
temperature testing. Otherwise, use the test fuel specified for general
testing. The two grades are specified in Table 1 of this section.
Table 1 of Sec. 1065.710.--Test Fuel Specifications for Gasoline
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Low temperature Reference procedure
Item Units General testing testing \1\
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Distillation Range:
Initial boiling ................ \2\ 24-35 24-36 .....................
point
10% point ................ 49-57 37-48 .....................
50% point [deg]C 93-110 82-101 ASTM D 86-01.
90% point ................ 149-163 158-174 .....................
End point ................ Maximum, 213 Maximum, 212 .....................
Hydrocarbon
composition:
1. Olefins [mu]m3/m3 Maximum, 100,000 Maximum, 175,000 .....................
2. Aromatics ................ Maximum, 350,000 Maximum, 304,000 ASTM D 1319-02.
3. Saturates ................ Remainder Remainder .....................
Lead (organic) g/liter Maximum, 0.013 Maximum, 0.013 ASTM D 3237-97.
Phosphorous g/liter Maximum, 0.0013 Maximum, 0.005 ASTM D 3231-02.
Total sulfur mg/kg Maximum, 80 Maximum, 80 ASTM D 1266-98.
Volatility (Reid Vapor kPa 2,3 60.0-63.4 77.2-81.4 ASTM D 323-99a.
Pressure)
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\1\ All ASTM standards are incorporated by reference in Sec. 1065.1010.
\2\ For testing at altitudes above 1 219 m, the specified volatility range is (52 to 55) kPa and the specified
initial boiling point range is (23.9 to 40.6) [deg]C.
\3\ For testing unrelated to evaporative emissions, the specified range is (55 to 63) kPa.
Sec. 1065.715 Natural gas.
(a) Natural gas for testing must meet the specifications in the
following table:
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278. Remove Sec. 1068.540.
[FR Doc. 04-19223 Filed 9-9-04; 8:45 am]
BILLING CODE 6560-50-P
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