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:
Feb. 08, 1983
Filed:
Jul. 07, 1980
David N Ball, Slough, GB;
Graviner Limited, High Wycombe, GB;
Abstract
A system for discriminating between radiation produced by a source of fire or explosion to be detected and that produced by a source not to be detected, comprises two radiation detectors 10, 12 respectively responsive to the intensity of radiation in different and spaced apart narrow wavelength bands. A rate of rise unit 22 and a threshold unit 24 responsive to detector 12 produce signals of a first binary type when the rate of, and the value of, the radiation intensity exceed predetermined values. A ratio unit 16 measures the ratio of the intensities of the radiation received by the two detectors and produces a signal of the opposite binary type when the ratio indicates that the source of radiation is a fire or explosion to which the system is not to respond. An AND gate 36 produces a fire and explosion indicating output only when the signals of the first type exist in the absence of the signal of the opposite type.