| 摘要 |
PROBLEM TO BE SOLVED: To determine quickly an abnormal state of a smoke detection function, and to prevent decline of measurement accuracy caused by a noise. SOLUTION: This smoke detector equipped with a light emitting circuit for allowing a light emitting element to emit light at each fixed period, and a light receiving element for receiving scattered light or attenuated light caused by smoke in a smoke detection part synchronously with the light emitting circuit, has a memory wherein a failure detection initial value which is a value corresponding to an output signal from the light receiving element when determined that a light emission quantity becomes smaller than usual by a failure, dirt or the like of the light emitting element is stored beforehand at a factory setting time in the smoke detector; and an abnormality determination means for determining that the smoke detector is abnormal based on light emission data corresponding to the output signal from the light receiving element at the light emission time from the light emitting element when monitoring the smoke detector and the failure detection initial value stored in the memory. COPYRIGHT: (C)2008,JPO&INPIT
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