State of the art is the so called USP; the Ultimate Sound Probe. It is an ultra miniature three dimensional sound probe that is capable of measuring broad banded sound pressure and particle velocity in three orthogonal directions. The USP mini is made for array applications or for applications where the standard USP is to large.

The USP is a compact and fully integrated sound probe that combines three orthogonally positioned particle velocity sensors and a miniature pressure microphone. The actual sensor configuration without its cap is less than 5×5×5mm³!

The USP extends the traditional possibilities for sound intensity measurements. A truly broad band frequency bandwidth (~2Hz-20kHz) without changing spacers becomes possible. Measurements under exceptional conditions become feasible, since the USP cannot only be used for keyhole measurements or small cavities, but also in a reactive field, in the near field and in the very near field. Only four channels are required for a full description of a 3D sound field (i.e. 3D intensity, energy and acoustic impedance), by measuring 3 particle velocity vector components and the (scalar) pressure.

Datasheet USP-mini