The electromagnetic ultrasonic probe for the electromagnetic ultrasonic inspection

摘要

PROBLEM TO BE SOLVED: To provide an electromagnetic acoustic wave inspection device using cross-correlation method for material surface inspection which can solve a problem such that an erroneous detection occurs because random noises prevent a small ultrasonic wave reflected by a surface defect from being detected due to low transmit-receive efficiency of ultrasonic wave.;SOLUTION: An electromagnetic acoustic wave probe for sending an ultrasonic wave and an electromagnetic ultrasonic wave probe for receiving an ultrasonic wave are located to face each other with a small clearance on the surface of an object to be inspected. The electromagnetic acoustic wave prove for receiving an ultrasonic wave receives a direct ultrasonic wave emitted from the electromagnetic acoustic wave probe for sending an ultrasonic wave and propagates in the clearance, and a defect ultrasonic wave reflected by a surface defect. After the received ultrasonic waves are amplified and digitized by an AD converter, a cross-correction function of the direct ultrasonic wave and the defect ultrasonic wave is calculated, and thereby the defect ultrasonic wave submerged with random noises can be detected.;COPYRIGHT: (C)2004,JPO