Patent ID: 6150935
Filing Date: 2000-11-21
Classification: G08B

Abstract:
A method of assessing the presence of a fire condition in one or more regions being monitored with an alarm system having a control unit linked to a plurality of displaced smoke detectors, the method comprising:establishing at the control unit records of the detectors associated with a plurality of pre-defined, regions being monitored by the alarm system;receiving at the control unit signals from the detectors indicative of a sensed level of smoke at the respective detectors;for at least the signal from a first detector, determining if a possible fire condition may be present in the vicinity of the first detector;responsive to said possible fire condition, determining if the record of the first detector exhibits a predetermined trend during a selected time interval, and, in response to the presence of the predetermined trend, producing a signal indicative of an alarm condition, but in the absence of the predetermined trend, evaluating the signal from another detector, located in the same region as the first detector and in the absence of a predetermined signal from the another detector, indicating a fault condition at the first detector.