1.1 This test method covers the field, or in situ measurement of sound power level by the two-surface method. The test method is designed to minimize the effects of reverberant conditions, directivity of the noise source under consideration, and the effects of ambient noise from other nearby equipment operating at the same time.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.