Ultrasonic non-destructive testing head - has composite piezo electric converter decoupled for independent variation reducing side lobes

摘要

A test head uses ultrasonic signals, transmitted via a piezoelectric transducer, which is fitted with attenuators, into the tested material. The transducer consists of several decoupled transducer elements, in order to reduce the level of the side lobes. The amplitudes of the decoupled transducers can be varied independently. The amplitude excitation is such that the acoustic signal is at a maximum at the centre of the transducer arrangement. Each transducer may be excited in a different phase, so as to control the main lobe. The transmitting and receiving section of the transducer may be separated by diodes. The receiver arrangement may provide central amplification, or peripheral attenuation, of the signals.