[Code of Federal Regulations]

[Title 33, Volume 1]

[Revised as of July 1, 2005]

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

[CITE: 33CFR67.10-20]



[Page 167-168]

 

                TITLE 33--NAVIGATION AND NAVIGABLE WATERS

 

         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY

 

PART 67_AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES

--Table of Contents

 

          Subpart 67.10_General Requirements for Sound signals

 

Sec. 67.10-20  Sound signal tests.



    (a) Sound signal tests must:



[[Page 168]]



    (1) Be made by the applicant in the presence of a Coast Guard 

representative, who certifies the test if the procedures comply with the 

requirements of this section;

    (2) Be made with Coast Guard supplied and calibrated sound level 

meters and power meters; and

    (3) Be made in an anechoic chamber large enough to accommodate the 

entire sound signal, as if installed for actual use.

    (b) The sound pressure level must be measured as a function of:

    (1) Distance by using a sufficient number of points to allow a far-

field extrapolation of the sound pressure level;

    (2) Power at outputs up to and including the approximate power level 

necessary to comply with Sec. 67.10-1(c);

    (3) Horizontal angle at increments not greater than 30[deg]; and

    (4) Harmonic content to at least the third harmonic.

    (c) In analyzing the test data to determine the minimum power 

necessary to produce the sound pressure level specified in Table A of 

this section the Coast Guard follows the procedures prescribed by the 

International Association of Lighthouse Authorities (IALA) in Supplement 

No. 3 to the IALA Bulletin of February 1969 for analysis of harmonic 

components and does not consider components above 1,100 Hertz as adding 

to the audible range.

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