Study on Ultrasonic Imaging With Bottom Echo

To improve the system gain and eliminate the dead zone in ultrasonic imaging testing, the method of ultrasonic imaging testing with bottom echo amplitude was studied. Comparative experiments were carried out on ZGS reference block to test the 9 flat bottom holes(FBH) with different depths by three imaging methods i.e. the ultrasonic defect echo amplitude imaging method, the ultrasonic defect echo depth imaging method and the ultrasonic bottom echo imaging method. It was shown by the experimental results that all the 9 FBHs were found with lower system gain by ultrasonic bottom echo imaging method, especially those sub-surface ones in the dead zone when using ultrasonic defect echo amplitude imaging method. It was proved that the ultrasonic bottom echo imaging method was a feasible and effective complement for the ultrasonic defect echo amplitude imaging method.