Subpart A - General Provisions

§ 325.1 - Scope of the rules in this part.

§ 325.3 - [Reserved]

§ 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.

§ 325.75 - Ground surface correction factors.

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

§ 325.79 - Application of correction factors.

Subpart G - Exhaust Systems and Tires

§ 325.91 - Exhaust systems.

§ 325.93 - Tires.