ANSI S1.21

Description / Abstract: Scope and Purpose. This standard describes a direct method and a comparison method for determining the sound power level produced by a source. This standard contains test room requirements, source location and operating conditions, instrumentation, and techniques for obtaining an estimate of the mcan-squarc sound pressure from which (lie sound power level of the source in octave or one-third octave bands is calcu-lated. It is intended to provide techniques for acous-tical measurements that can be used in test codes for particular types of equipment.