[Code of Federal Regulations]

[Title 40, Volume 24]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR201.22]



[Page 75]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 201_NOISE EMISSION STANDARDS FOR TRANSPORTATION EQUIPMENT; INTERSTATE 

RAIL CARRIERS--Table of Contents

 

                     Subpart C_Measurement Criteria

 

Sec.  201.22  Measurement instrumentation.



    (a) A sound level meter or alternate sound level measurement system 

that meets, as a minimum, all the requirements of American National 

Standard S1.4-1971 \1\ for a Type 1 (or S1A) instrument must be used 

with the ``fast'' or ``slow'' meter response chacteristic as specified 

in Subpart B. To insure Type 1 response, the manufacturer's instructions 

regarding mounting or orienting of the microphone, and positioning of 

the observer must be observed. In the event that a Type 1 (or S1A) 

instrument is not available for determining non-compliance with this 

regulation, the measurements may be made with a Type 2 (or S2A), but 

with the measured levels reduced by the following amount to account for 

possible measurement instrument errors pertaining to specific 

measurements and sources:

---------------------------------------------------------------------------



    \1\ American National Standards are available from the American 

National Standards Institute, Inc., 1430 Broadway, New York, NY 10018.



Table 1--Sound Level Corrections When Using a Type 2 (or S2A) Instrument

------------------------------------------------------------------------

                                                                Decibels

      Measurement section                   Source                 \1\

------------------------------------------------------------------------

201.24........................  Locomotives...................        0

                                Rail cars.....................        0

                                Locomotive load cell test             0

                                 stand.

201.26........................  Retarder......................        4

                                Car coupling..................        2

201.27........................  Locomotive load cell test             0

                                 stand.

                                Stationary locomotive.........        0

------------------------------------------------------------------------

\1\ Amount of correction to be subtracted from measured level (dB).



    (b) A microphone windscreen and an acoustic calibrator of the 

coupler type must be used as recommended by: (1) the manufacturer of the 

sound level meter or (2) the manufacturer of the microphone. The choice 

of both devices must be based on ensuring that Type 1 or 2 performance, 

as appropriate, is maintained for frequencies below 10,000 Hz.



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