FMSCA Regulation 325

Subpart A	General Provisions
325.1	Scope of the rules in this part.
325.3	Effective date.
325.5	Definitions.
325.7	Allowable noise levels.
325.9	Measurement tolerances.
Subpart B	Administrative provisions
325.11	Issuance, amendment, and revocation of the rules in this part.
325.13	Inspection and examination of motor vehicles.
Subpart C	Instrumentation
325.21	Scope of the rules in this subpart.
325.23	Type of measurement systems which may be used.
325.25	Calibration of measurement systems.
325.27	Use of a windscreen.
Subpart D	Measurement of noise emissions; highway operations
325.31	Scope of the rules in this subpart.
325.33	Site characteristics; highway operations.
325.35	Ambient conditions; highway operations.
325.37	Location and operation of sound level measurement system; highway operations.
325.39	Measurement procedure; highway operations.
Subpart E	Measurement of noise emissions; stationary test
325.51	Scope of the rules in this subpart.
325.53	Site characteristics; stationary test.
325.55	Ambient conditions; stationary test.
325.57	Location and operation of sound level measurement systems; stationary test.
325.59	Measurement procedure; stationary test.
Subpart F	Correction factors
325.71	Scope of the rules in this subpart.
325.73	Microphone distance correction factors.1
325.75	Ground surface correction factors.1
325.77	Computation of open site requirementsnonstandard sites.
325.79	Application of correction factors.
Subpart G	Exhaust systems and tires
325.91	Exhaust systems.
325.93	Tires.

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