Patent attributes
An optical smoke detector (110) is provided that comprises a housing (112) having a base (114) for attaching the detector to a surface and a cover (116) having a side wall (124) and a bottom wall (126) defining the interior of said cover. An optical sensor (131) is provided for generating a signal representative of the detected light and a control circuit (130) is provided for controlling operation of the detector. The control circuit (130) includes a plurality of temperature sensors (D1, D2) for sensing a rise in ambient temperature and generating a signal representative thereof. The temperature sensors (D1, D2) are located above an internal surface of said bottom wall (126) within the housing and are substantially equally spaced. The control circuit (30) is operable to compare said representative signal with a reference signal and generate an alarm signal in dependence thereon.
