CPC G08B 17/107 (2013.01) [G01N 15/06 (2013.01); G08B 29/28 (2013.01); G01N 2015/0046 (2013.01); G01N 2015/0693 (2013.01)] | 20 Claims |
1. A self-calibrating fire sensing device, comprising:
an adjustable particle generator and a variable airflow generator configured to generate aerosol having a particular particle size and optical scatter properties at a controllable density level;
a first transmitter light-emitting diode (LED) configured to emit a first light that passes through the aerosol;
a second transmitter LED configured to emit a second light that passes through the aerosol;
a photodiode configured to:
detect a scatter level of the first light that passes through the aerosol; and
detect a scatter level of the second light that passes through the aerosol; and
a controller configured to calibrate a gain of the photodiode based on the detected scatter level of the first light, the detected scatter level of the second light, and the controllable aerosol density level.
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