[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: 40CFR92.131]

[Page 464-465]
 
                   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. 92.131  Smoke, data analysis.

    The following procedure shall be used to analyze the smoke test 
data:
    (a) Locate each throttle notch test mode, or percent rated power 
setting test mode. Each test mode starts when

[[Page 465]]

the throttle is placed in the mode and ends when the throttle is moved 
to the succeeding mode. The start of the first idle mode corresponds to 
the start of the test sequence.
    (b) Analyze the smoke trace by means of the following procedure:
    (1) Locate the highest reading, and integrate the highest 3-second 
average reading around it.
    (2) Locate and integrate the highest 30-second average reading.
    (3) The highest reading occurring more than two minutes after the 
notch change (excluding peaks lasting less than 5 seconds, caused by 
such random events as the cycling of an air compressor) is the ``steady-
state'' value.
    (c)(1) The values determined in paragraph (b) of this section shall 
be normalized by the following equation:
[GRAPHIC] [TIFF OMITTED] TR16AP98.008

Where:

Nn is the normalized percent opacity, Nm is the 
average measured percent opacity (peak or steady-state), and L is actual 
distance in meters from the point at which the light beam enters the 
exhaust plume to the point at which the light beam leaves the exhaust 
plume.

    (2) The normalized opacity values determined in paragraph (c)(1) of 
this section are the values that are compared to the standards of 
subpart A of this part for determination of compliance.
    (d) This smoke trace analysis may be performed by direct analysis of 
the recorder traces, or by computer analysis of data collected by 
automatic data collection equipment.