Patent ID: 7638770
Filing Date: 2009-12-29
Classification: G01N,G08B

Abstract:
1. A method of detecting a fire condition in a monitored region including the operations of: (a) concurrently monitoring the region using: (b) using the band sensors to obtain n+2 measurement values of radiation intensity emitted from the monitored region in determining the presence or absence of the fire condition wherein the n+2 measurement values include: n measurement values obtained from the emission band sensors; one measurement value obtained from the first reference band sensor; and one measurement value obtained from the second reference band sensor and from which detection parameters are calculated, which are evaluated against at least one threshold in determining the presence or absence of the fire condition wherein the detection parameters include two respective reference ratios calculated for each of the n measurement values: a first reference ratio between respective n measurement values and the measurement value from the first reference band sensor; and a second reference ratio between respective n measurement values and the measurement value from the second reference band sensor.