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.

[1]  Gordon Hayward,et al.  Air coupled NDE-constraints and solutions for industrial implementation , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[2]  H. Lamb.  On waves in an elastic plate , 1917 .

[3]  M. J. Garcia-Hernandez,et al.  Ultra-low noise front-end electronics for air-coupled ultrasonic non-destructive evaluation , 2003 .

[4]  D. Hutchins,et al.  The use of air-coupled ultrasound to test paper , 2001, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[5]  W. Grandia,et al.  NDE applications of air-coupled ultrasonic transducers , 1995, 1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium.

[6]  Gordon Hayward,et al.  A model for low noise design of ultrasonic transducers , 1995, 1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium.