Absolute calibration of an acoustic emission sensor

Abstract

Calibrated sensors are essential for quantitative comparisons of acoustic emission source mechanics. We describe experimental techniques and mathematical models for implementation of an absolute sensor calibration scheme using glass capillary fracture and ball impact, two sources which can be easily implemented. Additionally, we describe the specific experimental procedures for absolute sensor calibration using the both the fracture of a glass capillary tube, and drop of a 0.4 mm ruby ball, as the calibration source. The mathematical formulation is based on a Green's function formalism. The Glaser-type conical piezoelectric sensor, used as an example in this study, has a noise floor of approximately 1 picometer displacement when coupled to steel. The amplitude of the sensor response is flat within 3 dB from 50 kHz to 2 MHz at a level of 0 dB relative to 1 V/nm. © RILEM 2013.