Consistency of surface pulse and reciprocity calibration of piezoelectric AE sensors

The calibration of piezoelectric acoustic emission sensors mainly includes two methods, reciprocity method and surface pulse method. The former uses the principle of electro-acoustic reciprocity of piezoelectric sensors, and the latter needs a reference capacitance or laser system for displacement or velocity measurement. Prior studies have indicated that the two methods had some consistency, but some scholars still questioned the reciprocity calibration of piezoelectric acoustic emission sensors. In this paper the equivalent and real reciprocity coefficient were calculated and compared to test their consistency. Experimental system was established to test and verify the results. The test results showed that the reciprocity and surface pulse method had good agreement.