| 摘要 |
<p>A smoke detecting apparatus comprises: a lamp (10); a light receiving element (20) for receiving light from the lamp (10); a smoke detecting circuit (1) for detecting the smoke density in accordance with the signal output from the light receiving element (20). The apparatus further comprises: a light emission failure detector (20, 50, 60) for detecting a light emission failure in which the lamp (10) fails to emit light in response to a light emission instruction from the smoke detecting circuit (1); a counter for counting light emission failures; and a memory (63) for storing the number of light emission failures. The apparatus may further comprise a warning unit (72, 73) which, when the number of failures becomes a predetermined value or more, warns that the lamp (10) will soon be exhausted. Thus, the unit enables a maintenance person to replace the lamp (10) without fail before it is exhausted. <IMAGE></p> |
