A PU Sound Intensity Probe Designed for High Temperature Use

Normal microphones can't resist high temperatures. The recently developed particle velocity microphone, can resist temperatures up to 300 degrees Celsius (570 degrees Farenheit). Current R&D is focused on increasing the upper temperature of the sensor element to 600 degrees Celsius (1300 degrees Farenheit).

A sound pressure (p) sensitive system is created with a particle velocity sensor, when it is placed in a small (4cm in length and 5mm in diameter) standing wave tube. This sound pressure arrangement is combined with a particle velocity sensitive (u) element and thus creating a pu (intensity) probe. All components of this novel sensor are made with special heat resistant materials.

A model of the temperature dependence is derived and checked by measurements. The frequency response, polar pattern, selfnoise etc. of both pressure and velocity microphone are determined.