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.
Patent No.:
Date of Patent:
Dec. 27, 1994
Filed:
Aug. 24, 1993
Kyoichi Ikeda, Tokyo, JP;
Tetsuya Watanabe, Tokyo, JP;
Hideo Tsukamoto, Tokyo, JP;
Takahiro Kudo, Tokyo, JP;
Kouji Nagai, Tokyo, JP;
Satoshi Fukuhara, Tokyo, JP;
Yokogawa Electric Corporation, Tokyo, JP;
Abstract
A semiconductor type differential pressure measurement apparatus is disclosed comprising a measuring diaphragm having its periphery fixed, and two measuring chambers, each having a predetermined spacing along both surfaces of the measuring diaphragm, and which detects differential pressure within allowable limits of measurement. When an overpressure is applied, the diaphragm is stopped by a wall of a measuring chamber to prevent the diaphragm from being damaged by overpressure, so that no additional mechanism is required to prevent damage from overpressure. One embodiment utilizes an additional chamber and overhang to reduce overpressure. Another embodiment utilizes a measuring chamber having the two sides of the diaphragm exposed to the ambient to eliminate need for a pressure resistant casing. In a further embodiment, injected impurities serve as a terminal.