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 a 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.
申请公布号
DE2737089(C2)
申请公布日期
1983.07.28
申请号
DE19772737089
申请日期
1977.08.17
申请人
SECURITY PATROLS CO. LTD.;KOKUSAI GIJUTSU KAIHATSU CO. LTD., TOKYO, JP
