Tokyo Shibaura Electric Co., Ltd.

Dainichi Machine and Engineering Co., Ltd.

Gijun Idei

Kunihiko Nakamura

Masao Kaizuka

Kazuma Takakura

A calibration device for a non-destructive inspection/measurement system is provided, including an excitation coil; a detection coil; and a computer that applies a sinusoidal signal or a combined signal including multiple sinusoids having mutually different frequencies to the excitation coil in order to excite a pipe body, and that detects changes in the output voltage of the detection coil. The calibration device calibrates the detection results in the computer by entering, as variables in simultaneous equations, the amplitudes and phase differences of the output voltage of the detection coil at multiple calibration points of known thickness on the pipe body. The calibration device performs calibrations by using multiple different calibration conditions at each of the calibration points, and entering, into the simultaneous equations, the amplitudes and phase differences of the output voltage of the detection coil for each of the calibration conditions.

Calibration device for non-destructive inspection/measurement system and non-destructive inspection/measurement method

In conventional non-destructive inspection devices using magnetism, the subject of inspection was limited to the surface layer of the test object as a result of the skin effect, and it was not possible to perform flaw detection inspection at the interior or reverse surface of thick-structured test objects. The effect of the surface effect was eliminated by imparting an external signal canceling the detection output of the test object surface layer from the detection output of a magnetic field resulting from eddy currents induced in the test object. As a result, it has become possible to extract the detection output of the test object interior that had been masked by the detection output of the test object surface layer, and it has become possible to perform thickness inspection and flaw detection of the reverse surface and interior or a test object.

Nondestructive inspection device using alternating magnetic field, and nondestructive inspection method

A voltage follower circuit comprises an input terminal; an output terminal; first and second power supply terminals; a first transistor of one conductivity type having a base connected to the input terminal; a second transistor, opposite in conductivity type to the first transistor, having a base connected to the collector of the first transistor, a collector connected to the output terminal and an emitter connected to the first power supply terminal; a third transistor having a base and collector connected to the output terminal and an emitter connected to the emitter of the first transistor; a fourth transistor of the one conductivity type having an emitter connected to the second power supply terminal; and a fifth transistor of the one conductivity type having an emitter and base respectively connected to the emitter and base of the fourth transistor and a collector connected to the base of the fourth transistor and to the first power supply terminal through a resistor.

Voltage follower circuit

A constant voltage circuit comprises first and second circuit terminals; a current source connected to said first and second circuit terminals; a first npn transistor whose collector is connected to the first circuit terminal through a resistor; a second npn transistor having a collector connected to the emitter of the first npn transistor, a base connected to the collector of the first npn transistor, and an emitter connected to the second circuit terminal; a third npn transistor having a base connected to the base of the first npn transistor, an emitter connected to the emitter of the first npn transistor through a resistor and a collector connected to the first circuit terminal through a resistor; a fourth transistor having a base connected to the collector of the third transistor and a collector and emitter coupled to the first and second circuit terminals; a resistor connected between the first circuit terminal and a junction of the bases of the first and third transistors; and a resistor connected between the second circuit terminal and a junction between the bases of the first and third transistors.

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Yokohama, Japan

Gijun Idei