Considerations for Developing Calibration Standards for Acousto-Ultrasonic Inspection

Abstract

The advent of a calibration standard for use in ultrasonic inspection practices meant that ultrasonic inspection could be applied with some degree of repeatability and reliability. This paper is intended to be a starting point for similar development, or at least the opening frame of discussion, of a calibration standard in the technology of acousto-ultrasonic inspection. This paper identifies and discusses parameters used to define the pulse that generates the simulated acoustic emission event. The purpose is to alert the operator/engineer to potential variability in the output of systems. This variability can exist due to slight changes in the characteristics of the pulse. Items that are discussed include pulse rate, height, width, and rise/fall time. It was discovered that slight changes in some of these characteristics can have a dramatic effect on the energy detected by the receiving sensor. This illustrates the need for at least two types of calibration standards. This paper discusses numerous considerations for calibration standards.