| 摘要 |
<p>Smoke detector particularly provided for fire alarm with a radiation source (5) having a conical radiation diagram and a radiation receiver (R) located onto the axis but out of reach of the direct radiation which collects the radiation diffused within the conical annular area (C). To limit the parasite light falling onto the receiver, the radiation area (C) is defined by elements located outside the direct collecting area of the receiver for example, in the radiation direction, by pieces (S) located behind the collecting surface and laterally by screens (B, K) of which the edges are concealed by another screen (B"), of the radiation receiver. </p> |
