Hitachi, Ltd.

Mitsuo Ai

Yoshitaka Matsuoka

Satoshi Shimada

Takeo Nagata

Kazuji Yamada

Yasumasa Matsuda

Motohisa Nishihara

Yoshimi Yamamoto

Masanori Tanabe

Masatoshi Tsuchiya

Michitaka Shimazoe

Yukio Takahashi

Akira Ikegami

Ko Soeno

Yutaka Sakurai

Tsutomu Okayama

Tomio Yasuda

Hideyuki Nemoto

Katsuya Katohgi

Keiji Miyauchi

A differential pressure transducer having a cantilever and a semiconductor strain gauge attached to each side of the cantilever at an intermediate portion of the latter. The cantilever has one end fixed by electron beam welding to a fixing member and the other end left for free displacement in response to a differential pressure. The displacement of the other end of the cantilever is detected as changes in the electric resistances of the semiconductor strain gauges.

Differential pressure transducer

A pressure transducer comprising a silicon diaphragm on which a semiconductor strain gauge is formed and which has a diaphragm portion deformable in response to a pressure, an insulating support which is made of borosilicate glass having the silicon diaphragm rigidly mounted thereon and which is provided with a pressure introducing hole in its central part, a metallic support which is cylindrical, which is made of an iron-nickel alloy similar in the thermal expansion coefficient to the borosilicate glass and on which the glass insulating support is rigidly mounted, and a metallic housing within which the integrated structure consisting of the silicon diaphragm, the glass insulating support and the metallic support is arranged; the silicon diaphragm, the insulating support and the metallic support being joined by the anodic bonding, the metallic support being rigidly welded to the metallic housing at its lower end part.

Pressure sensitive apparatus

A pressure transducer has at least one pressure transmitting space filled with liquid, a space for a pressure to be sensed connected to the pressure transmitting space through a diaphragm, and a pressure sensitive element in the pressure transmitting space for transducing a pressure transmitted from the space for the pressure to be sensed to the pressure transmitting space through the diaphragm to an electrical signal. A printed circuit board wired to electrically connect terminals of the pressure sensitive element is arranged closely to the element and thin temperature sensitive elements for temperature-compensating the pressure sensitive element are arranged on the printed circuit board.

Pressure transducer

A semiconductor pressure transducer comprising a disc-shaped pressure-responsive diaphragm; a pair of radial strain gauge units having a piezoresistance effect, formed by injecting an impurity in the radial direction in the surface of the diaphragm; and a pair of tangential strain gauge units having a piezoresistance effect, formed by injecting an impurity in the tangential direction in the surface of the diaphragm, wherein the distance from the pair of the radial strain gauge units to the center of the circular diaphragm is greater than the distance from the pair of the tangential strain gauge units to the center of the circular diaphragm.

Semiconductor pressure transducer

A semiconductor transducer comprising an improved strain-yielding body yielding a strain in response to the impartation of a force or displacement, and a semiconductor strain gauge bonded to the strain-yielding body. The improved strain-yielding body is made of an iron-nickel-cobalt alloy containing 28.2 to 31.0% by weight of nickel and 15.0 to 19.5% by weight of cobalt. This iron-nickel-cobalt alloy is initially heated up to a temperature above 600.degree. C. for the purpose of standard heat treatment for removing its internal strain. After the standard heat treatment, the iron-nickel-cobalt alloy is subjected to cold working at a working rate of more than and including 60%, and is then subjected to heat treatment at a temperature between 350.degree. C. and 600.degree. C. The heat-treated iron-nickel-cobalt alloy is shaped into the predetermined form of the strain-yielding body.

Semiconductor transducer

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Katsuta, Japan

Mitsuo Ai