Hitachi, Ltd.

Katsuya Katohgi

Satoshi Shimada

Kazuji Yamada

Yasumasa Matsuda

Motohisa Nishihara

Yoshitaka Matsuoka

Hideo Sato

Yukio Takahashi

Masanori Tanabe

Tsutomu Okayama

Michitaka Shimazoe

Mitsuo Ai

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 bridge circuit with four arms including semiconductor strain gauge elements has input terminals for coupling a DC power supply with a pair of diagonally opposite junctions of the bridge circuit per se and output terminals coupled with a pair of remaining diagonally opposite junctions. Initial zero-point temperature compensators each are connected in series and in parallel to each of semiconductor strain gauge elements on adjacent two arms of the bridge circuit. Temperature compensators for zero-point shift adjustment are each provided between the adjacent arms closer to each output terminal. A temperature compensator for span adjustment is provided between one of the input terminals and the DC power source. A constant current control unit for feeding a constant current to the bridge circuit is provided between the other input terminal and the DC power supply.

Semiconductor strain gauge with temperature compensator

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Katsuta, Japan

Katsuya Katohgi