Ultrasound is simply a name given to sound waves whose frequency (pitch) is too high to be detected by the human ear. The use of low‐intensity ultrasonic waves in level measurement, flow detection, and medical imaging is well known. Here, a pulse of ultrasound is used to ‘probe’ the sample under investigation; comparison of the pulse shape before and after transmission, and a measurement of the transit time in the sample can provide information on many physical parameters. For these applications, the intensity of the ultrasonic burst is not sufficient to affect the material, and no chemical or physical changes are involved.
MCB UP Ltd
Copyright © 1991, MCB UP Limited