Patent ID: 11900791
Assignee: HONEYWELL INTERNATIONAL INC.
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. A method of operating a self-testing fire sensing device, comprising:
measuring a quantity of any dust or smoke particles in an optical scatter chamber prior to activating a fan of the self-testing fire sensing device;
comparing the measured quantity to a previously measured quantity of particles in the optical scatter chamber;
activating the fan to remove any dust or smoke particles from the optical scatter chamber responsive to the measured quantity being greater than the previously measured quantity of particles;
deactivating the fan;
measuring a quantity of smoke particles in the optical scatter chamber responsive to deactivating the fan;
comparing the quantity of smoke particles measured responsive to deactivating the fan to the previously measured quantity of particles;
reporting a confirmed fire responsive to the quantity of smoke particles measured responsive to deactivating the fan being equal to or greater than the previously measured quantity of particles; and
reporting a false alarm responsive to the quantity of smoke particles measured responsive to deactivating the fan being less than the previously measured quantity of particles.