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:
Aug. 07, 1990
Filed:
May. 20, 1988
David F Sorrells, Jacksonville, FL (US);
Parker Electronics, Inc., Jacksonville, FL (US);
Abstract
A pressure sensor for accurate readings of low pressures utilizes an ultrasonic transmitter which sends a signal to a movable diaphragm via a waveguide. Pressure changes across the diaphragm causes changes in the signal path length from transmitter to receiver which are translated into pressure readings via electronic circuitry employing phase comparator circuitry. The received signal is split into two signals one of which is shifted in phase. A temperature responsive controller selects which received signal is used in a comparison with the transmitted signal thus greatly extending the temperature range over which the sensor operates. The use of an ultrasonic waveguide with a length of at least twice the frequency of the transmitted signal coupled to the transmitter eliminates echoes and reflections and provides for enhanced accuracy in reading even very low pressures.