[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.311-79]

[Page 596]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 86_CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND 
ENGINES--Table of Contents
 
Subpart D_Emission Regulations for New Gasoline-Fueled and Diesel-Fueled 
           Heavy-Duty Engines; Gaseous Exhaust Test Procedures
 
Sec. 86.311-79  Miscellaneous equipment; specifications.

    (a) Chart recorders. (1) The minimum chart speed allowed is 3 inches 
per minute for gasoline-fueled engines and 0.5 inches per minute for 
Diesel engines.
    (2) When testing gasoline-fueled engines all chart recorders 
(analyzers, torque, rpm, etc.) shall be provided with Automatic markers 
which indicate one second intervals. Preprinted chart paper (one second 
intervals) may be used in lieu of the automatic markers provided the 
correct chart speed is used.
    (b) Accuracy of temperature meas urements. (1) The following 
temperature measurements shall be accurate to within 1.2 [deg]C:
    (i) Temperature measurements used in calculating the engine intake 
humidity:
    (ii) The temperature of the fuel in volume measuring flow rate 
devices;
    (iii) The temperature of the sample within the water trap(s).
    (2) All other temperature measurements shall be accurate within 2.5 
[deg]C.
    (c) Intake air humidity and temperature measurements. (1) Humidity 
conditioned air supply. Air that has had its absolute humidity altered 
is considered humidity-conditioned air. For this type of intake air 
supply, the humidity measurements must be made within the intake air 
supply system, and after the humidity conditioning has taken place.
    (2) Nonconditioned air supply. Humidity measurements in non-
conditioned intake air supply systems must be made in the intake air 
stream entering the supply system. Alternatively, the humidity 
measurements can be measured within the intake air supply stream.
    (3) Engine intake air temperature measurement must be made within 48 
inches of the engine. The measurement location must be made either in 
the supply system or in the air stream entering the supply system.
    (d) Sample component surface temperature. For each component (pump, 
sample line section, filters, etc.) in the heated portion of the 
sampling system that has a separate source of power or heating element, 
use engineering judgment to locate the coolest portion of that component 
and monitor the temperature at that location. If several components are 
within an oven, then only the surface temperature of the component with 
the largest thermal mass and the oven temperature need be measured.
    (e) If water is removed by condensation, the sample gas temperature 
or sample dew point must be monitored either within the water trap or 
downstream. It may not exceed 7 [deg]C (45 [deg]F).

[42 FR 45154, Sept. 8, 1977, as amended at 46 FR 50495, Oct. 13, 1981; 
47 FR 49807, Nov. 2, 1982]