| 摘要 |
PURPOSE:To measure easily and in a non-destractive state by computing a frequency distribution area, making backscattering noises of the time when ultrasonic waves continuously changed in frequency are propagated within a measured object analyzing a frequency, and integrating those results. CONSTITUTION:An ultrasonic wave probe 13 is put on a measured object 11 consisting of metal and ultrasonic waves continuously changed in frequency are transmitted from the probe 13 by an ultrasonic transceiver 15. The ultrasonic waves make irregular reflection at a grain boundary 14 within the measured object 11 when propagated through the measured object 11, and the backscattering noises 19 turn back halfway. The frequency and backscattering noise strength are integrated and the frequency distribution area is computed after these noises 19 are analyzed by a frequency analyzer 29 and the relation of the frequency and the backscattering noise strength are computed. Next, a grain size can be measured simply, quickly and in a non-destructive state on checking the frequency distribution area value with the previously prepared relation of grain size and frequency distribution area because proportional relation exists between a frequency distribution area and a grain size. |
