Patent ID: 6202490
Filing Date: 2001-03-20
Classification: G01B,G01N

Abstract:
A nondestructive testing apparatus comprising:a wave transmitter for injecting an acoustic elastic wave into an measurement object on the basis of a magnetically excited current;a magnetically excited current feeding device for feeding the magnetically excited current to said wave transmitter;a wave receiver for detecting an acoustic elastic wave propagating through the measurement object and for outputting a received wave signal;a filter for putting a band limit to the received wave signal;an automatically amplifying rate controlling function-equipped amplifier for amplifying a signal outputted from said filter to a given amplitude and for outputting the signal to said magnetically excited current feeding device; anda signal processor for extracting from said wave receiver a signal of an oscillation frequency of a positive feedback loop composed of said wave transmitter, the measurement object, said wave receiver, said filter, said amplifier and said magnetically excited current feeding device and for processing the signal.