SMOKE DETECTION METHOD Russian patent published in 2005 - IPC

FIELD: signaling systems and systems for detecting the presence of air-borne smoke particles in environment.

SUBSTANCE: method involves periodical emitting light pulses; receiving reflected light flux by photosensor, wherein light flux is reflected at an angle different from optical radiation axis; measuring charge-discharge cycle durability of photosensor included in RC-circuit in absence of light pulses to be emitted t₁ and that in presence of the light pulses t₂; comparing the difference between t₁ and t₂ values |t₁-t₂|=k with predetermined one and determining smoke absence/presence and operational reliability of optical channel from above comparison.

EFFECT: increased operational reliability due to control operational capability and cleanliness level of optical channel, possibility to turn to digital circuit technology.

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