Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Kazuo Takaku

Masahiro Otaka

Makoto Hayashi

Tasuku Shimizu

Kunio Hasegawa

Akisuke Naruse

Kunio Enomoto

Toshihiko Yoshimura

Yuichi Ishikawa

Shigeru Kajiyama

Hiroshi Kimura

Masahiro Koike

Satoshi Kanno

Shinji Sakata

Toshiyuki Sawa

Sadato Shimizu

Toshiyuki Furukawa

Hirotsugu Fujimoto

Sigeru Kajiyama

Tatsukuma Hosono

Stephen Evanson

Yuko Koguchi

Masahiro Ootaka

Akira Akasu

A nondestructive inspecting apparatus is arranged to have an exciting magnet for applying an ac magnetic field to a sample and a SQUID for converting change of a magnetic characteristic of the sample occurring when the ac magnetic field is applied to the sample into an electric signal. The exciting magnet is a cancelled coil assembly composed of plural coils having respective polarities.

Apparatus with cancel coil assembly for cancelling a field parallel to

A fluxmeter includes an application unit for applying a magnetic field, a superconducting quantum interference element and a flux transmitting circuit. The flux transmitting circuit includes a pickup coil formed of a superconducting print coil and a core for the pickup coil. The core is formed of a soft magnetic material. The core serves to suppress the leakage of magnetic flux to magnetically couple the pickup coil and the superconducting quantum interference element efficiently to improve the sensitivity and resolution of the fluxmeter. The pickup coil may be manufactured by photolithography, sputtering, laser beam deposition, MBE deposition, MOCVD or spray pyrolysis.

Fluxmeter including squid and pickup coil with flux guiding core and

A non-destructive inspection apparatus includes a magnetic field applying device and a magnetic sensor. The magnetic field applying device is adapted to apply DC and AC magnetic fields to an object to be inspected. Degradation/damage of the object is detected by measuring a magnetic characteristic of the object in a state in which the DC and AC magnetic fields are applied. Also, a non-destructive inspection apparatus includes as a magnetic sensor a plurality of pickup coils and a SQUID(s) connected to the pickup coils and decides the form of a defect of an object to be inspected by producing a difference between outputs of the pickup coils or SQUIDs.

Apparatus for inspecting degradation/damage of a material using an AC

On the basis of a finding that a magnetic hysteresis of a metal material, among magnetization characteristics changing with secular degradation of the metal material, shows a clear correspondence with the degree of degradation of the metal material, a change in such a magnetization characteristic is measured to estimate the degree of secular degradation of the metal material. In a typical embodiment, a superconducting quantum interference device is used to detect the magnetization characteristic of a measuring object. According to the present invention, the degree of embrittlement of a metal material used in an environment of high temperatures can be quickly detected in a non-destructive fashion so that the danger of brittle fracture of the metal material can be reliably prevented.

Apparatus for magnetically detecting degradation of metal material using

A distance measuring apparatus and method using an acoustic signal. It includes a transmitting probe for transmitting an acoustic signal from a transmitter, a plurality of receiving probes having resonance frequencies different from the central frequency of the signal transmitted from the transmitting probe, and a control circuit for controlling the functions of those probes. The acoustic signal is received by a receiving probe having a resonance frequency which provides the maximum received-signal sensitivity at the central frequency of the received acoustic signal under the control of the control circuit to thereby measure a long distance accurately.

Distance measuring apparatus and method

On the basis of a finding that a magnetic hysteresis of a metal material, among magnetization characteristics changing with secular degradation of the metal material, shows a clear correspondence with the degree of degradation of the metal material, a change in such a magnetization characteristic is measured to estimate the degree of secular degradation of the metal material, In a typical embodiment, a superconducting quantum interference device is used to detect the magnetization characteristic of a measuring object. According to the present invention, the degree of embrittlement of a metal material used in an environment of high temperatures can be quickly detected in a non-destructive fashion so that the danger of brittle fracture of the metal material can be reliably prevented.

Method and apparatus utilizing a magnetic field for detecting

Measurement of a physical property such as coercive force of a member to be inspected is performed at a plurality of locations in one region of the member. Similar measurement is performed in a plurality of different regions of the member and a maximum or minimum value (extreme value) is determined for each of the regions. On the basis of the extreme values thus determined, a recurrence period is determined in accordance with an extreme value statistic theory with the aid of a computer, whereon an estimated maximum value of the physical property of the member as a whole is determined from the recurrence period. On the basis of the estimated maximum value, the degree of deterioration of the member is predicted by the computer by consulting the data indicating the previously determined relation between the physical property and the degree of deterioration.

Method and apparatus for predicting deterioration of a member

Method and apparatus for inspecting surface defects

A guide apparatus comprises an annular rail and jaws for attaching the annular rail onto a cylindrical member to be inspected by an inspecting probe on the rail. The attaching jaws are provided on the rail and include at least two radially stationary jaws and at least one radially movable jaw. Each of the radially stationary jaws has a jaw surface to be abutted on an outer periphery of the cylindrical member. A radial distance between the abutting surface of the radially stationary jaw and the inner peripheral surface of the rail is discontinuously variable.

Guide apparatus

A rail apparatus for running an automatic ultrasonic flaw detector around a reactor pressure vessel for detecting any flaw in the weld beads on the reactor pressure vessel. At least two circumferential rails and vertical rails are connected through turn tables at their crossing points to form a rail unit. The rail unit has vertical rails extending upward from the uppermost circumferential rail. The vertical rails are secured to a gamma shield, so that the rail unit as a whole is suspended from the gamma shield by means of these vertical rails. The rail unit is provided with swing prevention devices for preventing swing thereof. In installation of the rail apparatus, the rail unit is temporarily mounted on the reactor pressure vessel before mounting the latter in a containment vessel. Then, after accurately placing the reactor pressure vessel together with the rail unit in a right place within the containment vessel, the rail unit is supported suitably by the gamma shield.

Rail apparatus around nuclear reactor pressure vessel and method of

An ultrasonic flaw detector for detecting any flaw existing in the inner peripheral corner section of the joint portion between the barrel of a nuclear reactor pressure vessel and each of a plurality of cylindrical nozzles projecting from the barrel, by means of an ultrasonic wave applied from the outer peripheral corner section of the joint portion. The flaw detector has a probe pivotable around an axis which is made to follow up the locus of the center of curvature in the rounded surface of the outer peripheral corner section during the movement of the probe around the nozzle. According to this arrangement, it is possible to achieve a full automatic and remote control of the flaw detector except the attaching and detaching of the same, and to facilitate the processing of the signals representing the result of the flaw detection.

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Hitachi, Japan

Kazuo Takaku