Primary calibration of Acoustic Emission sensors by the method of Reciprocity : theoretical and experimental considerations
Résumé
This paper is focused on the calibration of acoustic emission (AE) sensors by means of the reciprocity method. Therefore, the problem of the reciprocity criterion in the case of ultrasonic waves in solid is addressed. This latter criterion is well established and widely used for the calibration of electro-acoustic transducer. However, and despite that the first papers have been publish ed forty years ago, its application in the case of ultrasonic wave in solids now raises a number of discussions in the community of acoustic emission. To start with, we present a review of the concept of reciprocity since its origin in electromagnetism to its application to electro- acoustic transducers. We follow a critical analysis on the validity of the reciprocity theorem in the case of AE sensors. Next, a new aperture function will be presented. Finally, an original method for shear wave calibration of AE sensors will be presented.