ALARM UNIT

摘要

PROBLEM TO BE SOLVED: To provide an alarm by simply detecting abnormality due to a suspended particulate matter including a suspended particulate by using a detection function of a smoke particulate by focusing on a residential fire alarm provided with a scattered light type smoke sensor structure.SOLUTION: A sensor part 14 intermittently drives a light emission part 24 to emit light at a predetermined cycle. A light-receiving signal received by a light receiving part 26 is amplified by a light receiving amplification 30 set with an amplification gain for fire detection, and a smoke density detection signal is outputted. When a fire is detected by the smoke density detection signal in a control part 12, a fire alarm is notified from a notification part 16. The control part 12, upon detection of a floating particulate prediction operation received by an operation part 18, increases a detection sensitivity by changing the amplification gain for fire detection of the light receiving amplification part 30 to the amplification gain for the floating particulate, outputs the floating particulate density detection signal by amplifying the light receiving signal based on reception of a scattering light of a floating particulate matter, and when the floating particulate density is more than a predetermined floating particulate detection threshold value, a floating particulate abnormality is detected, and a floating particulate alarm is outputted by instructing the notification part 16.