| 摘要 |
PURPOSE:To prevent the blank time in a smoke detection operation by being generated by detecting the non light emission of a light emitting lamp and alarming that the limit of the life of the light emitting lamp is close when the number of the times of the non light emission is more than the prescribed number of times. CONSTITUTION:From the time when a smoke sensor 1 is installed or a xenon lamp 10 is exchanged, the number of times when the xenon lamp 10 does not emit the light at the time to emit the light, that is, the number of the times of the non light emission is stored every month. That is, when a light emitting level by a light receiving element 20 does not arrive at a prescribed level at the time of a light emitting instruction from a control circuit 50, the number of the times of the non light emission is increased by '1.' Then, the number at every month is stored in an EEPROM 63. The total number of the times of the non light emission in the month and the figure of an alarm level, 7 times for instance, are compared by the control circuit 50 every month and a life alarm signal is outputted when the total number of the times of the non light emission in the month is more than 7. Thus, the failure of the xenon lamp 10 can be recognized beforehand and the blank period in the smoke sensing operation is not generated. |
