Discriminating fire sensor with thermal override capability

Claim 1

A fire sensor apparatus for detecting a fire, comprising: multi-channel fire sensor means for sensing radiation, including first channel sensing means for detecting radiation in a first spectral band that includes radiation in the 0.7-1.2 wavelength region of the electromagnetic frequency spectrum and for providing a first sensor signal corresponding to the amount of radiation sensed in said first spectral band, second channel sensing means for detecting radiation in a second spectral band that includes radiation in the 7-30 micron wavelength region of the electromagnetic frequency spectrum and for providing a second sensor signal corresponding to the amount of radiation detected in said second spectral band, and gate means responsive to said first and said second channel sensing means for providing a first output signal when said first and said second sensor signals exceed first and second thresholds, respectively, associated with the detection of a predetermined fire to be sensed; heat sensor means for providing a second output signal in response to a predetermined amount of detected radiation in the 7-30 micron wavelength region associated with heat energy incident on said fire sensor apparatus, said predetermined amount being greater than said second threshold associated with the second channel sensing means; OR gate means, having first and second inputs connected respectively to receive said first and said second outputs, adapted to provide a third output signal in response to either said first or said second output signals; high energy ammunition round discrimination means for providing an inhibit signal in response to predetermined detected radiation associated with a high energy ammunition round impacting in the vicinity of said fire sensor apparatus; and output gate means for providing a fourth output signal for activating a fire suppressant in response to said third output signal in the absence of said inhibit signal whereby the second output signal from said heat sensor will normally cause the fire suppressant to be activated even though one or more of the first or second channel sensing means is not operating properly.

Claim 4

A system for detecting a fire and activating a fire suppressant in response thereto, said system comprising: a primary fire detector having first and second sensor means therein, said first sensor means being adapted to generate a first output signal in response to detection of radiation in a first spectral band exceeding a first predetermined threshold level, said second sensor means being adapted to generate a second output signal in response to detection of radiation in a second spectral band exceeding a second predetermined threshold, said primary fire detector including gating means providing a primary output signal adapted to activate a fire suppressant in response to the generation of the first and second output signals from the sensors of the primary fire detector; thermal override sensing means for generating an override output signal in response to detection of a predetermined amount of radiation associated with heat exceeding a third threshold level; and activating means for activating a fire suppressant in response to either the generation of the primary output signal from the primary fire detector or the override signal from the thermal override sensing means whereby said thermal override sensing means will cause the fire suppressant to be activated even though one or more of the sensors in the primary fire detector fail to operate properly.

Claim 5

A system for detecting a fire and activating a fire suppressant in response thereto, said system comprising: a primary fire detector having first and second sensor means therein, said first sensor means being adapted to generate a first output signal in response to detection of radiation in a first spectral band exceeding a first predetermined threshold level, said second sensor means being adapted to generate a second output signal in response to detection of radiation in a second spectral band exceeding a second predetermined threshold, said primary fire detector including gating means providing a primary output signal adapted to activate a fire suppressant in response to the generation of the first and second output signals from the sensors of the primary fire detector; thermal override sensing means for generating an override output signal in response to detection of a predetermined amount of radiation associated with heat exceeding a third threshold level; and activating means for activating a fire suppressant in response to either the generation of the primary output signal from the primary fire detector or the override signal from the thermal override sensing means whereby said thermal override sensing means will cause the fire suppressant to be activated even though one or more of the sensors in the primary fire detector fail to operate properly.