| 摘要 |
A smoke detector having a closed internal optical path can detect airborne particulate matter, such as smoke from a fire, via a light scattering sensor and/or a light absorption sensor. The path can be implemented with a plurality of reflectors, such as piezoelectric minors. Input light can be coupled to the path, on a pulsed basis, for example via one of the minors, in a resonant condition.
|
