A PU Sound Intensity Probe Designed for High Temperature Use 2007-01-2336
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.