The Kansai Electric Power Co., Inc.

H & B System Co., Ltd.

Kozo Keikaku Engineering Inc.

Nobuki Dohi

Mitsuo Okumura

Hong Zhang

Masayuki Hirose

Masashi Kameyama

Yukihisa Hasegawa

A transmission probe and a reception probe for transmitting and receiving a wideband ultrasonic wave are provided. Each time when the locations of the probes and are moved, a received wave G(t) is obtained. Based on a spectrum F(f) corresponding to the received wave G(t), a narrowband spectrum FA(f) is extracted. A component wave GA(t) corresponding to the narrowband spectrum FA(f) is found by inverse Fourier transformation. A longitudinal wave primary resonance frequency fhaving a relationship with a thickness W (mm) of an inspection target and a primary resonance frequency fof a transverse wave generated by mode conversion are calculated. A comparative display of the component waves GA(t) is presented using f, fand sizing coefficients n, n, nand nfor high precision inspection. Based on the measurement point which shows a wave generation in the comparative screen of the component waves GA(t), it is determined that there is a flaw Z at a certain position inside the inspection target immediately below a line segment connecting the transmission probe and the reception probe.

Ultrasonic inspection method utilizing resonant phenomena

A flaw Z with a long probing length inside a probing target is allowed to be probed. The waves other than the probing target waves are removed or reduced, so that the individual difference in the sizing result due to the ability of the measuring personnel is eliminated to improve the precision of the probing. A transmission probeand a receiving probefor transmitting and receiving a wide band ultrasonic wave are included. Each time the positions of the probesandare moved, a received wave G(t) is obtained. From a spectrum F(f) corresponding to the received wave G(t), a narrowband spectrum FA(f) is extracted. A component wave GA(t) corresponding to the narrow band spectrum FA(f) is obtained by inverse Fourier transformation. The component wave GA(t) is provided for a comparative display using a predetermined sizing coefficient. The position of a flaw Z is determined inside a probing targetright below the line segment connecting the centers of the transmission probeand the receiving probe, based on at which of the measurement points a wave is generated on the comparative display screen.

Ultrasonic probing method and apparatus therefor utilizing resonance phenomenon

Growing community of inventors

Fukui, Japan

Nobuki Dohi