Abstract: 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 Gj(t) is obtained. Based on a spectrum Fj(f) corresponding to the received wave Gj(t), a narrowband spectrum FAj(f) is extracted. A component wave GAj(t) corresponding to the narrowband spectrum FAj(f) is found by inverse Fourier transformation. A longitudinal wave primary resonance frequency f1 having a relationship with a thickness W (mm) of an inspection target and a primary resonance frequency fS1 of a transverse wave generated by mode conversion are calculated. A comparative display of the component waves GAj(t) is presented using f1, fS1 and sizing coefficients ns1, ns2, ns3 and ns4 for high precision inspection.

Abstract: 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 Gj(t) is obtained. Based on a spectrum Fj(f) corresponding to the received wave Gj(t), a narrowband spectrum FAj(f) is extracted. A component wave GAj(t) corresponding to the narrowband spectrum FAj(f) is found by inverse Fourier transformation. A longitudinal wave primary resonance frequency f1 having a relationship with a thickness W (mm) of an inspection target and a primary resonance frequency fS1 of a transverse wave generated by mode conversion are calculated. A comparative display of the component waves GAj(t) is presented using f1, fS1 and sizing coefficients ns1, ns2, ns3 and ns4 for high precision inspection.

Abstract: 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 probe 31 and a receiving probe 32 for transmitting and receiving a wide band ultrasonic wave are included. Each time the positions of the probes 31 and 32 are moved, a received wave Gj(t) is obtained. From a spectrum Fj(f) corresponding to the received wave Gj(t), a narrowband spectrum FAj(f) is extracted. A component wave GAj(t) corresponding to the narrow band spectrum FAj(f) is obtained by inverse Fourier transformation. The component wave GAj(t) is provided for a comparative display using a predetermined sizing coefficient.

Abstract: 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 probe 31 and a receiving probe 32 for transmitting and receiving a wide band ultrasonic wave are included. Each time the positions of the probes 31 and 32 are moved, a received wave Gj(t) is obtained. From a spectrum Fj(f) corresponding to the received wave Gj(t), a narrowband spectrum FAj(f) is extracted. A component wave GAj(t) corresponding to the narrow band spectrum FAj(f) is obtained by inverse Fourier transformation. The component wave GAj(t) is provided for a comparative display using a predetermined sizing coefficient.

Abstract: While a transmitting transducer (2a) for transmitting an ultrasonic wave and a receiving transducer (2b) for receiving an ultrasonic wave are moved within a predetermined circular region (7) on a surface of a material being measured, ultrasonic waves are transmitted and received 10,000 times. Then, arithmetic averaging is performed every time an ultrasonic wave is received, on the ultrasonic wave and ultrasonic waves that have been received until then. For example, the aforementioned predetermined frequency is given by ((n±(½))×(106×v/&Dgr;L))(Hz), where &Dgr;L is a variation in distance between the transmitting transducer and the receiving transducer, v is a transmission velocity of an ultrasonic wave transmitting in a material being detected, and n is a natural number.

Abstract: While a transmitting transducer (2a) for transmitting an ultrasonic wave and a receiving transducer (2b) for receiving an ultrasonic wave are moved within a predetermined circular region (7) on a surface of a material being measured, ultrasonic waves are transmitted and received 10,000 times. Then, arithmetic averaging is performed every time an ultrasonic wave is received, on the ultrasonic wave and ultrasonic waves that have been received until then. For example, the aforementioned predetermined frequency is given by ((n±(1/2))×(106×v/&Dgr;L))(Hz), where &Dgr;L is a variation in distance between the transmitting transducer and the receiving transducer, v is a transmission velocity of an ultrasonic wave transmitting in a material being detected, and n is a natural number.

Abstract: While a transmitting transducer (2a) for transmitting an ultrasonic wave and a receiving transducer (2b) for receiving an ultrasonic wave are moved within a predetermined circular region (7) on a surface of a material being measured, ultrasonic waves are transmitted and received 10,000 times. Then, arithmetic averaging is performed every time an ultrasonic wave is received, on the ultrasonic wave and ultrasonic waves that have been received until then. For example, the aforementioned predetermined frequency is given by ((n±(½))×(106×v/&Dgr;L))(Hz), where &Dgr;L is a variation in distance between the transmitting transducer and the receiving transducer, v is a transmission velocity of an ultrasonic wave transmitting in a material being detected, and n is a natural number.