High-Sensitivity and Wide-Band AE Transducer with Concave Piezoelectric Element and Conical Backing

Abstract

This paper reports some experimental results on a concave piezoelectric element, conical backing and first amplifier for high-sensitivity and wide-band AE transducer. The piezoelectric element, conceived according to a “resonance dispersion” design, was fabricated based on piezoelectric ceramics/polymer 1-3 connectivity composites by Newnham. To control ringing characteristics, the backing was conical in shape. The first amplifier was inserted in a FET zero-bias amplifier in a cable connecter. The AE transducer had half sensitivity and a wider resonance frequency (100kHz-1.9MHz) than a conventional type AE transducer (resonance frequency; 180kHz). The residual noise was 20μVp-p (10kHz-50MHz) at first stage amplifier, the measurement of hold level was able to reduce the noise to 10μV with a wide frequency. Using this AE transducer, AE measurement with a high-sensitivity and wide-band was realized in material testings.