Intensity probes

The intensity-measurement technique is a powerful tool for locating sound sources, order rank them and determine the emitted sound power. The method is based on the simultaneous determination of sound pressure and particle velocity by two closely spaced microphones. The sound intensity probe must ensure a well-defined acoustic spacing between the microphones as well as minimise disturbances to the sound field.

To ensure maximum measurement accuracy, the spacing between the micro-phones must be optimised for the given measurement conditions. At low frequencies, in highly reverberant conditions, this spacing must be large, whereas for measurements at high frequencies, it must be small.