Wide dynamic range electronics for air-coupled Lamb-waves ultrasonic NDT using piezoelectric transducer arrays

The excitation and front-end electronics for an ultrasonic transducer array used in an air-coupled NDT system is presented. The main characteristic of the whole system is its wide dynamic range, making possible the inspection of thin and porous materials. The system is composed of two 32 elements concave array with a resonant frequency of 780 kHz. To excite the transducers, an array of pulsers has been designed. The transducers are excited by 500 ns and 500 V electrical pulses. The receivers are ultra low noise amplifiers with a 10 MHz bandwidth and 80 dB of gain.