Reference source for the calibration of acoustic emission measurement

Acoustic Emission (AE) is a widely used technique for the integrity testing of many structures and is still growing with its use in process, condition and health monitoring. Its use is however limited by the current inability to gain any useful quantitative information from the measurements made. This is due to the fact that the quantitative information gathered is mostly a function of the structure of about which little is known, and is in most applications complex. Without reliable quantitative measurement, transfer of information between measurement systems will always be relative. This paper proposes a technique that aims to make the calibration of AE measurements possible with the use of a reference source. The use of the energy descriptor and a suitable calibrated reference source will allow in-situ calibrations of complete AE measurement systems, allowing quantitative measurements to be made on the calibrated system. The reference source discussed is a conical shaped piezoelectric transducer with a point contact tip. Its linearity with energy has been shown to be very good and its calibration has been demonstrated using an elastic ball impact