A Low-Cost Intensity Probe

Sound Intensity is a useful measure in acoustics because in a reverberant environment free-field measurements can be done. The proposed low cost intensity probe combines a sound particle velocity sensor and a microphone, which can be used as separate devices or in one package. For the latter case the velocity and the pressure are measured at almost the same location. Since the intensity is calculated from the cross-correlation of the velocity and pressure, a very accurate phase matching, as for the p-p method, is not necessary; and its signal to noise ratio (SNR) is higher than for the separate sensors. The data-acquisition and processing is implemented on a standard personal computer, combined with a simple calibration, and thus creating a very powerful intensity measuring device.