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:
Mar. 14, 2000
Filed:
Feb. 14, 1997
Steven S Sunshine, San Carlos, CA (US);
David C Bliven, San Jose, CA (US);
John Seymour Mattis, Sunnyvale, CA (US);
Underground Systems, Inc., Armonk, NY (US);
Abstract
A method and apparatus for continuously monitoring and measuring the concentration of gases in a gas-containing liquid such as a transformer oil. The method and apparatus employ a passive gas extraction technique which comprises a high performance membrane material to extract dissolved gases from the oil, and an IR-based sensor to detect gases present. The passive gas extractor extracts dissolved gas from the gas-containing liquid, there being a known relationship between the concentration of a constituent gas in the extracted gas and the concentration of the constituent gas remaining dissolved in the gas-containing liquid. The gas sensor senses the concentration of a constituent gas in the extracted gas, in the presence of other constituent gases. The gas sensor comprises a sample chamber which receives the extracted gas, a non-dispersive infrared (IR) absorption sensing system which generates an electrical signal corresponding to the light absorption, at one or more specified IR wavelengths, of the extracted gas in the chamber, and an electrical output comprising the electrical signal generated by the non-dispersive IR absorption sensing system. A processor having receives the electrical signal corresponding to the light absorption, at the one or more specified IR wavelengths, of the extracted gas in the chamber, and computes the concentration of at least one gas constituent present in the extracted gas.