Patent ID: 7948628

Claim:
A fire detector comprising; a housing having at least one window; a source of electromagnetic radiation; one or more sensors for sensing radiation emitted by a flame; a first reflector; a second reflector associated with the electromagnetic radiation source, the second reflector being arranged to focus radiation from the source through the window onto the first reflector; and a measuring and processing unit mounted within the housing, wherein the one or more sensors are operatively associated with the measuring and processing unit so as to provide the measuring and processing unit with an input indicative of the electromagnetic radiation reaching the one or more sensors; wherein the electromagnetic radiation source and the one or more sensors are mounted within the housing, and the reflector is mounted outside the housing; and wherein the first reflector is positioned to reflect electromagnetic radiation from the source passing out through the window back through the window onto the one or more sensors wherein the one or more sensors sense both the reflected electromagnetic radiation passing through the window and electromagnetic radiation emitted by the flame.