[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR92.107]

[Page 425]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 92--CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES--
Table of Contents
 
                       Subpart B--Test Procedures
 
Sec. 92.107  Fuel flow measurement.

    (a) Fuel flow measurement for locomotive and engine testing. The 
rate of fuel consumption by the engine must be measured with equipment 
conforming to the following:
    (1) The fuel flow rate measurement instrument must have a minimum 
accuracy of 2 percent of measurement flow rate for each 
measurement range used. An exception is allowed at idle where the 
minimum accuracy is 10 percent of measured flow rate for 
each measurement range used. The measurement instrument must be able to 
comply with this requirement with an averaging time of one minute or 
less, except for idle, dynamic brake, and notches 1 and 2 where the 
instrument must be able to comply with this requirement with an 
averaging time of three minutes or less.
    (2) The controlling parameters are the elapsed time measurement of 
the event and the weight or volume measurement. Restrictions on these 
parameters are:
    (i) The error in the elapsed time measurement of the event must not 
be greater than 1 percent of the absolute event time. This includes 
errors in starting and stopping the clock as well as the period of the 
clock.
    (ii) If the mass of fuel consumed is measured by discrete weights, 
then the error in the actual weight of the fuel consumed must not be 
greater than 1 percent of the measuring weight. An exception 
is allowed at idle, where the error in the actual weight of the fuel 
consumed must not be greater than 2 percent of the measuring 
weight.
    (iii) If the mass of fuel consumed is measured electronically (load 
cell, load beam, etc.), the error in the actual weight of fuel consumed 
must not be greater than 1 percent of the full-scale value 
of the electronic device.
    (iv) If the mass of fuel consumed is measured by volume flow and 
density, the error in the actual volume consumed must not be greater 
than 1 percent of the full-scale value of the volume 
measuring device.
    (3) For devices that have varying mass scales (electronic weight, 
volume, density, etc.), compliance with the requirements of paragraph 
(a)(1) of this section may require a separate flow measurement system 
for low flow rates.
    (b) Calibration. Fuel flow rate measurement devices shall be 
calibrated against an independent measurement of the total mass of fuel 
dispensed during a fixed amount of time in accordance with the following 
provisions:
    (1) Measurement of the total mass shall have an accuracy and 
precision of 1 percent of point, or better.
    (2) Fuel measurements shall be performed for at least 10 flow rates 
evenly distributed over the entire range of fuel flow rates used during 
testing.
    (3) For each flow rate, either the total mass of fuel dispense must 
exceed 5.0 kilograms (11.0 pounds), or the length of time during which 
the fuel is dispensed must exceed 30 minutes. In all cases, the length 
of time during which fuel is dispensed must be at least 180 seconds.