[Code of Federal Regulations]

[Title 49, Volume 5]

[Revised as of October 1, 2005]

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

[CITE: 49CFR325.77]



[Page 16-17]

 

                        TITLE 49--TRANSPORTATION

 

                      DEPARTMENT OF TRANSPORTATION

 

PART 325_COMPLIANCE WITH INTERSTATE MOTOR CARRIER NOISE EMISSION STANDARDS

--Table of Contents

 

                      Subpart F_Correction Factors

 

Sec. 325.77  Computation of open site requirements--nonstandard sites.



    (a) If the distance between the microphone location point and the 

microphone target point is other than 50 feet (15.2 m), the test site 

must be an open site within a radius from both points which is equal to 

the distance between the microphone location point and the microphone 

target point.



[[Page 17]]



    (b) Plan view diagrams of nonstandard test sites are shown in 

Figures 3 and 4. Figure 3 illustrates a test site which is larger than a 

standard test site and is based upon a 60-foot (18.3 m) distance between 

the microphone location point and the microphone target point. (See 

Sec. 325.79(b)(1) for an example of the application of the correction 

factor to a sound level reading obtained at such a site.) Figure 4 

illustrates a test site which is smaller than a standard test site and 

is based upon a 35-foot (10.7 m) distance between the microphone 

location point and the microphone target point. (See Sec. 325.79(b)(2) 

for an example of the application of the correction factor to a sound 

level reading obtained at such a site.)

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