ISO 3745:1977

Acoustics — Determination of sound power levels of noise sources — Precision methods for anechoic and semi-anechoic rooms

Specifies two laboratory methods. Gives requirements for the test room as well as the source location, operating conditions and instrumentation. Specifies techniques for obtaining an estimate of the surface sound pressure level from which the weighted sound power level of the source and the sound power level in octave or one-third octave bands may be calculated.