A calibrated capacitance transducer for the detection of acoustic emission

Abstract

The authors describe a capacitance transducer for use as a calibrated detector of energetic acoustic emission events. It is displacement-sensitive with a wide frequency response, and typically has a rise-time of 20 ns. The electrical output of the transducer has been calibrated as a function of displacement, and the device has been tested in a broad-band acoustic emission system. It is envisaged that the transducer could either be used to measure emission transients directly, or act as a reference against which conventional piezoelectric transducers could be compared.