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:
Sep. 20, 1988
Filed:
Apr. 20, 1987
George L Kerber, San Diego, CA (US);
Harper J Whitehouse, San Diego, CA (US);
Linear Measurements, Inc., San Diego, CA (US);
Abstract
A method and the resulting article for providing a nearly zero temperature coefficient pressure transducer preferably comprising a cylindrical capacitor whose capacitance is a function of both externally applied pressure and, undesirably, of temperature. The variation of capacitance with temperature may be greatly minimized by selectively choosing a transducer material characterized by particular parameter constants such that the temperature coefficient of Young's modulus (.alpha..sub.E) is equal in magnitude but opposite in sign to the temperature coefficient of linear expansion (.alpha..sub.l). Moreover, the thermal variation of capacitance can be further minimized by selectively choosing a transducer material whose temperature coefficient of linear expansion and of Young's modulus are nearly zero. Fabricating a capacitance pressure transducer from materials characterized by .alpha..sub.E and .alpha..sub.l which are both equal and opposite in sign and/or very small in magnitude will greatly reduce the high pressure, temperature sensitivity of the transducer, especially when compared with the temperature sensitivity under pressure characteristics of conventional fused quartz pressure transducers.