| 摘要 |
PURPOSE:To prevent the blank period of a smoke sensing operation from being generated by detecting the non light emission of a light emitting lamp corresponding to a light emitting instruction and predicting the failure of the light emitting lamp beforehand. 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 the light emitting instruction from a control circuit 50, the number of the times of the non light emission is increased only by one. To put it concretely, a function (n) for indicating how many months are there before the month is set to '1' and the function An for indicating the number of the times of the non light emission in the (n)-th month is set to '0.' Thereafter, after every lapse of one month, the function (n) is increased by '1' and the function An is reset to '0.' Record is stored in an EEPROM 63 at every reset. Thus, the failure of the xenon lamp 10 can be recognized beforehand. |
