Patent ID: 6011478
Filing Date: 2000-01-04
Classification: G08B

Abstract:
A smoke sensor comprising:light receiving means for temporally alternately receiving scattered light of two different wavelengths .lambda..sub.1 and .lambda..sub.2 ;calculating means for performing a calculation required for smoke detection, on a scattered light output y of the wavelength .lambda..sub.1 and a scattered light output g of the wavelength .lambda..sub.2 from said light receiving means; andsmoke detection processing means for performing a smoke detection process on the basis of a calculation result output from said calculating means, said calculating means estimating an output value of one of the scattered light output y of the wavelength .lambda..sub.1 and the scattered light output g of the wavelength .lambda..sub.2 which are temporally alternately output from said light-receiving means, at a sample timing of the other output, and obtaining a ratio of the estimated output value of the one scattered light at the sample timing of the other output to an output value of the other scattered light, as a two-wavelength ratio.