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:
Oct. 23, 1984
Filed:
Jun. 10, 1983
Richard H Frische, Phoenix, AZ (US);
Rudolf C Dankwort, Phoenix, AZ (US);
Charles D Klem, Phoenix, AZ (US);
Sperry Corporation, New York, NY (US);
Abstract
A quartz crystal vibrating diaphragm pressure sensor includes a primary quartz crystal body having a diaphragm formed therein and electrodes on each side of the diaphragm for piezoelectrically exciting thickness shear mode oscillations of said diaphragm, said oscillations varying in frequency in accordance with variations in fluid pressures applied to the surfaces of said diaphragm. A second identical or substantially identical diaphragm similarly excited but exposed to a constant pressure provides a reference frequency for providing precision difference frequency pressure measurement and for inherently compensating for ambient conditions affecting both diaphragms.