Evaluation of measurement accuracy of a sound intensity probe

Abstract

The two‐microphone sound intensity measurement technique is most commonly used. There are several causes of measurement error with this technique. Some of them are inherent in the technique itself, and others are due to the imperfect performance of the microphone probes. Various types of measurement errors are reviewed first. Then, the measurement accuracy of a one‐dimensional, four‐microphone probe is discussed. The accuracy of the intensity measurement can be evaluated either in an acoustic tube or in an anechoic chamber. The effective distances between pairs of microphones, active and reactive intensities, and particle velocities measured by use of the probe in an anechoic chamber are presented. These results, including the directivity patterns, are compared with those of a conventional intensity probe. The residual intensity index of the present probe is also presented.