Pulse Mode Study of the Ultrasonic Field Radiated by a Thick Piezoelectric Disc

摘要

The ultrasonic fields radiated by transducers excited in the pulse mode have been the subject of important theoretical works, but there have been very few experimental verifications. The characteristics of the pulsed field produced by a damped transducer have recently been studied by Weight and Hayman, using two complementary techniques: a Stroboscopic visual display of the wave fronts and a quasi-point measurement of the local pressure by means of a miniature probe. We were interested in the field radiated by a thick transducer excited by a short current pulse, the point measurements being obtained by means of a miniature probe of the same type as that described by Weight. Under pulse conditions, it has been proved experimentally that a thick transducer enables very short duration plane wave fronts to be set-up, without it being necessary to damp the rear face, which it is always difficult to do adequately. We have also shown ourselves that such a transducer could be very simply used as a wide-band reference transmitter. The object of this paper is to study the effect of the lateral dimensions of this transducer on the pulsed ultrasonic field that it generates. (ERA citation 11:005929)