ULTRASONIC PROBING METHOD AND ITS DEVICE UTILIZING RESONANCE PHENOMENON

摘要

A flaw (Z) inside a body (30) to be detected having a large scattering attenuation can be probed, and waves except for a detecting target are removed or reduced to thereby eliminate a difference in sizing results due to abilities of different measurers and provide a higher-accuracy probing. A transmission probe (31) and a reception probe (32) for respectively transmitting and receiving a wide-band ultrasonic wave are used to obtain a reception wave G<SUB>j</SUB>(t) every time the location positions of respective probes (31, 32) are moved, narrow-band spectrum FA<SUB>j</SUB> (f) is extracted from spectrum F<SUB>j</SUB> (f) corresponding to the reception wave G<SUB>j</SUB> (t), a component wave GA<SUB>j</SUB> (t) corresponding to the narrow-band spectrum FA<SUB>j</SUB> (f) is obtained by inverse Fourier transform, a component wave GA<SUB>j</SUB> (t) is compared and displayed using a specified sizing coefficient, and whether or not a flaw (Z) exists inside the body (30) to be detected directly under a line segment connecting the centers of the transmission probe (31) and the reception probe (32) is judged based on the presence or absence of waves occurring at respective measuring points on the comparative screen of the component wave GA<SUB>j</SUB> (t).