PRECISE KEASUREMENT OF SAW VELOCITY WIT11 AN INTERDIGITAL TRANSDUCER

A method of measuring the acoustic properties of materials using an interdigita1 transducer (IDT) for nondestructive evaluation (NDE) is described. An IDT can efficiently radiate acoustic waves directly into a liquid so that it is used as the acoutic wave transducer in the NDE system. In this paper, a new method for the measuring of SAW velocity by using the IDT is described. The output voltage is measured as a function of the frequency of the acoustic wave in the NDE system using an IDT. The SAW velocity is obtained from the frequency dependence. Measurement are made for an anisotropic materials at frequencies from 15 to 25 I'IIJz. The experimental results obtained in this manner agreed well with the theoretical ones.