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:
Jul. 03, 1979
Filed:
Aug. 17, 1977
Shunsaku Nakauchi, Mitaka, JP;
Security Patrols Co., Ltd., Tokyo, JP;
Abstract
The present invention is concerned with a flame sensing system utilizing infra-red rays by resonant radiation of carbon dioxide which system gives no erroneous information due to discharge of thunder, solar light or the like and has high sensitivity and S/N ratio. The flame sensing system according to the invention is characterized in that a flame is detected continuously for a short time in terms of difference in intensity between a first infra-red rays of a first wavelength produced by resonant radiation of carbon dioxide and a second infra-red rays of a wavelength located in the vicinity of said first wavelength in the region of wavelength in which there is little absorption by carbon dioxide in the air and then a warning device is actuated while the intensity of said second infra-red rays remains beyond a predetermined level.