Hitachi, Ltd.

The Tokyo Electric Power Company, Incorporated

Chubu Electric Power Company, Inc.

The Chugoku Electric Power Co., Inc.

Hitachi Nuclear Engineering Co., Ltd.

Yoshihiro Michiguchi

Kazuo Hiramoto

Fuminobu Takahashi

Masatsugu Nishi

Shigeru Izumi

Masahiro Koike

Mitsuo Suzuki

Hajime Umehara

Makoto Senoh

Yoshiaki Nagashima

Shinji Sonoda

Izumi Kobayashi

Kenichi Fujiwara

Satoshi Tanisaka

Kimio Yamada

Masao Sato

Yuuji Hashimoto

Ultrasonic waves from a transmit device are transmitted to an object subject to measurement. A surface reflected wave propagated in a contact medium and reflected at the surface of a tube and bottom surface reflected waves passing through an oxidation layer on the tube and reflected at the inner surface of the tube are convened into electric signals. A feature extracting part 5, in consideration of a correlation relationship of energy with respect to the frequency of a received signal, based on the received signal of ultrasonic waves converted to electric signals, extracts a signal feature data determined beforehand which has a strong correlation relationship with the thickness of a measured part. Based on the extracted signal feature data, a thickness conversion part references a relationship storage part which has stored therein beforehand a function that shows a relationship between the signal feature data and the thickness of the oxidation layer, and obtains the thickness of the oxidation layer.

Method and apparatus for measuring thickness of layer using acoustic

In visualizing an unknown object possessed by a person to be checked, a narrow pulsating radio wave beam is scanned over the whole surface of the person to observe the intensity of a reflected radio wave at each scan point. The frequency of the radio wave beam is set at a frequency easy to be transmitted by the human body to suppress the reflection from the human body and emphasize the unknown object to thereby discriminate between them. An image of the person to be checked is displayed and the portion having a strong reflection is color-displayed on the image to allow the check of the unknown object possessed by the person without contacting the person.

Method of detecting unknown object and apparatus therefor

Method and apparatus for detecting an object by using a radio wave which is radiated by an antenna toward the object to be detected. An echo wave of the radio wave reflected from the object is received by the antenna. On the basis of phase difference between the transmitted waveform and the received waveform, material of the object is discriminatively identified. The object is displayed as an image on a display unit.

Method and system for detecting an object with a radio wave

An object detecting method and apparatus is disclosed and which operates by transmitting a wave toward an object embedded in a medium having a reflective coefficient at its surface, receiving the resultant reflected wave from the object, applying the received signal to a signal processing unit, and displaying the results of signal processing by the signal processing unit on a display unit. The apparatus and method, furthermore, incorporates the means or steps of multiplying the received signal by a reference signal corresponding to the high frequency wave of the radiation energy and with its phase shifted by a controlled amount, so that the frequency of a signal component included in the received signal as a result of wave reflection from the surface of the medium is converted into a frequency which can be removed by a low-pass filter, passing the resultant received signal through the low-pass filter, and applying the output signal of the low-pass filter to the signal processing unit for processing a clear and sharp image reproduction of the object on a display.

Method and apparatus for detecting an object or a condition indicating a

Method and apparatus for evaluating location of an unknown sound generated in a structure such as a pressure vessel. A plurality of sound detectors are mounted on the structure for detecting sounds generated in the structure. On the basis of sound information of the unknown sound source derived from the outputs of the detectors, the location where the unknown sound is produced is determined. To this end, reference sounds are first generated at a plurality of known reference sound source positions, wherein information of the reference sounds derived from the outputs of the detectors are stored in a storage unit. Equi-pattern-distance curves each of which is in an equal pattern distance between a supposed unknown sound source and each of the reference sound sources are calculated on the basis of the reference sound information. The equi-pattern-distance curves are further corrected in accordance with the reference sound information. Upon occurrence of an unknown sound, pattern distances between the desired reference sound source positions and the unknown sound source position are calculated through pattern recognition procedure from the sound information derived from the outputs of the detector and the reference sound information stored. On the basis of the calculated pattern distances and the equi-pattern-distance curves, the position of the unknown sound source is determined. On the basis of the position of the unknown sound source, kinetic energy thereof may be arithmetically determined.

Unknown sound evaluating method and apparatus

A spark monitor device arranged to detect a high frequency noise due to a spark generated in a current collector of a rotary electric machine and monitor a state of spark generation on the basis of the product of a peak value of the high frequency noise exceeding a given set value and a time interval during which the peak value exceeds the set value.

Spark monitor device for current collectors

A number of sound detectors are provided on an external enclosure of a pressure vessel of a nuclear reactor. Output signals produced from the individual detectors are combined into a pattern in terms of time difference of the detector output signals relative to the time point at which the detected signal is first produced in response to the sound signal and relative peak values of the detector output signals relative to the magnitude of the output signal produced by the detector which detects the sound signal with the highest sensitivity. The pattern thus obtained is then compared with patterns which have been previously prepared by intentionally producing the sound signals at locations in interest within the pressure vessel, to thereby estimate the location within the pressure vessel at which the sound is produced.

Method of locating sound generation within enclosure

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Ibaraki, Japan

Yoshihiro Michiguchi