Kabushiki Kaisha Kobe Seiko Sho

Masayoshi Iwasaki

Norio Suzuki

Yoshiro Nishimoto

Shoji Nasu

Hitoshi Utsumi

Yoshikazu Mori

Kenji Aburatani

Kazuo Miyake

Sadao Kawashima

Hiroaki Yasukuni

Takehiko Ooshiro

Kousuke Sahara

A signal processing method in an electromagnetic induction test. A test object is subjected to an electromagnetic induction by use of N (N.gtoreq.1) kinds of test frequencies to obtain M (M.ltoreq.2N) kinds of phase detection outputs corresponding to respective states of the test object. The phase detection outputs are then sampled at a plurality of measuring points so that there exists n (n&lt;M) kinds of disturbance factors of which a portion contribute to the electromagnetic induction test. The phase detection outputs have a variance greater than a variance of a target parameter of the test object and contribute to the electromagnetic induction test. A first coordinate axis Z, is determined in a direction in which a variance of a distribution of the group of the measuring points comes to be a maximum in an M-dimensional space formed with the coordinate axes associated with the M kinds of the phase detection outputs. The remaining coordinate axes are likewise determined. Based on the coordinate of each of the measuring points viewed from the coordinate axis Z.sub.n+1, a measuring is effected to determine a presence or an absence of a defect, a physical quantity, and a geometric quantity on a surface of the test object.

Signal processing method for an electromagnetic induction test

A plurality of ultrasonic transducers or probes are positioned around a region of an object such as a steel tube to be inspected. One of the ultrasonic transducers is energized to emit an ultrasonic beam into the region, and ultrasonic waves reflected from and transmitted through the region in response to the emitted ultrasonic beam are received. Sound pressures are then measured from the reflected and transmitted ultrasonic waves, and an evaluation value is produced by arithmetically dividing the sound pressure of the reflected ultrasonic wave by the sound pressure of the transmitted ultrasonic wave.

Method of and apparatus for ultrasonic flaw detection

For the inspection of a square billet, an ultrasonic testing technique using an angle beam is performed using a phased array system. The phased array probe is disposed in a plane perpendicular to the axial direction of a square billet, at a prescribed distance from the surface of the billet and set at a prescribed angle with respect to the billet surface. The billet is inspected both inside and at the surface layer when the ultrasonic beam is electronically scanned. Inspection of the surface layer only is also performed using a surface defect inspection apparatus. Determination of internal defects (including subsurface defects) is performed based on the subtraction of information from the surface defect inspection from the information from the ultrasonic inspection.

Inspection method of square billet using electronic scanning

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Miki, Japan

Masayoshi Iwasaki