HIGH SIGNAL-TO-NOISE RATIO ULTRASONIC TESTING SYSTEM USING CHIRP PULSE-COMPRESSION

A new ultrasonic testing system using chirp pulse compression is descr ibed in this article. An improvement of the Signal-to-Noise Ratio (SNR ) of more than 20 dB can be achieved with this system compared to conv entional ultrasonic testing systems using a spike pulse. The special f eature of the system is a digital pulse compression with a finite impu lse response digital filter to compress the chirp pulse accurately and flexibly. The high SNR of the system provides more reliable automatic testing and allows the use of low-sensitivity transducers.