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. 10, 1993
Filed:
Sep. 24, 1991
David B Chang, Tustin, CA (US);
Victor Vali, Laguna Hills, CA (US);
Keith V Pearson, Long Beach, CA (US);
Albert F Lawrence, San Diego, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
An evanescent wave liquid level sensor for measuring the density-compensated level of a liquid in a container. The sensor employs an eccentric core optical fiber fully immersed in the liquid to be measured. Light is injected into one end of the fiber. Some of the light will be lost due to evanescent wave losses. Changes in the ratio of the intensity of the input light and the reflected light are due solely to changes in the density of the liquid. Changes in the liquid density can then be used to compensate a liquid level measurement. Since the liquid temperature is related to its density, the sensor can also be used to measure changes in the liquid temperature.