The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 07, 1991

Filed:

Nov. 23, 1988
Applicant:
Inventors:

Satoshi Shimada, Hitachi, JP;

Yasushi Shimizu, Katsuta, JP;

Seiichi Ugai, Hitachi, JP;

Assignee:

Hitachi, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01L / ;
U.S. Cl.
CPC ...
73721 ; 73727 ; 73756 ; 338-4 ;
Abstract

A differential pressure transmitter is an improvement over the drawbacks of conventional apparatuses and provides a differential pressure transmitter which compensates for adverse effects of a static pressure by using a static pressure detecting piezoresistive gauge. The transmitter includes a highly sensitive static pressure sensor with high outputs, and a composite sensor with small crosstalk between the static pressure sensor and a differential pressure sensor. The differential pressure transmitter is constructed of semiconductor sensor substrate and a fixed mount on which the sensor substrate is securely mounted; whereby the differential pressure of a fluid is detected by utilizing the difference in Young's modulus between the sensor substrate and the mount. The sensor substrate is processed on one side or on both sides to make a part of the sensor substrate thinner than the surrounding parts and thereby cause a peak stress due to a static pressure load to occur at the thin part, and a change in resistance of a semiconductor piezoresistive gauge formed at that thin portion is detected.


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