Comparative study of wide-band ultrasonic transducers

The relative performance of several types of ultrasonic transducer are assessed using reproducible acoustic transients generated from Q-switched Nd:YAG laser pulses incident on an aluminium alloy sample. A laser interferometer, a capacitance transducer, two types of electromagnetic acoustic transducers (EMATs), and a broad-band piezoelectric transducer are examined as detectors. The comparison includes a study of their rise-times, and typical signal-to-noise ratios. In the case of the interferometer and capacitance transducer, displacement measurements are shown to be highly consistent with theory.