The Cylindrical Microphone Array for the Measurement of Sound Power Level: Number and Arrangement of Microphones

摘要

The concept of a cylindrical microphone array and measurement surface was introducedrecently [1] as an alternative to the parallelepiped array for the measurement of product noiseemissions. The latter is currently one of the two arrays permitted in international standardsand industry test codes, but there are several problems associated with its use. A follow-uppaper [2] included details of a proposed procedure for using the cylindrical array that couldreadily be incorporated into international standards on sound power level measurements. Thepresent paper describes measurements taken in conformance with that procedure on a 1.75-mrack source using a variety of microphone positions over the cylindrical measurement surface.Conclusions are drawn regarding prudent choices for the number of microphones, equalvs unequal areas, and traversing vs fixed -point implementations of the cylindrical array.