Properties of the Coupled Vibration mode AE Sensor for Partial Discharge Detection

The properties of coupled vibration mode AE(Acoustic Emission) sensor, and non-coupled vibration mode AE sensor was investigated on high sensitivity. The resonant type of AE sensitivity. The resonant type of AE sensor for the experiment was fabricated as air backing structure, and the piezoelectric element was composed of EC-65 with 0.1 wt% of WO₃additives. The maximum sensitivity of the coupled vibration mode AE sensor was 64.3 dB at the resonant frequency of 166 kHz. and that of the non-coupled mode AE sensor was 58.9 dB at the resonant frequency of 265 kHz. The sensitivity of the non-coupled measurement of the AE sensor was made using NIST transient surface wave calibration method(ASTM E1106-86). The coupled vibration mode AE sensor responded higher than the non-coupled vibration mode AE sensor to the partial discharge occurred in the needle and plate electrode, and the peak frequency of the partial discharge was 150 kHz