Benefits of signal processing in ultrasonic inspection

This paper describes a number of the benefits which signal processing techniques have brought to the analysis of ultrasonic data. In view of the steady growth in the use of the ultrasonic time of flight diffraction (TOFD) technique, many of the examples are taken from TOFD data. However, all of the processing techniques described are non-specific and could be applied to data obtained using either the pulse echo (PE) or TOFD techniques. Overall, to achieve these benefits from signal processing, there is a fundamental requirement to be able to store, analyse and compare more than one ultrasonic trace (A-scan). Thus the paper is concerned with what can be achieved by the use of digital ultrasonic systems, rather than with simple flaw detectors