| 摘要 |
PURPOSE:To speedily and accurately judge a fire by setting a high threshold value for judging a fire from the detected value of a smoke detector when the detected temperature of a temperature detector is low and high and also setting a high threshold value when the detected temperature is intermediate. CONSTITUTION:When the detected temperature theta of the temperature detector 2 installed on a ceiling surface is lower than a room temperature DELTA+5 deg.C or >=60 deg.C, the threshold value Sr of threshold control circuit 7 which judges a fire from the detected value S of a smoke detector 1 installed at the same place is set low to 15%/m below DELTA+5 deg.C or 8%/m above 60 deg.C. When the detected temperature is intermediate between the room temperature DELTA+5 deg.C and 60 deg.C, the threshold value Sr of the threshold control circuit 7 is set high to 30%/m. Consequently, a fire misjudgement due to the heat and smoke of cooking, heat of air conditioning, and smoke of a cigarette is securely precluded and, specially, a smoking fire which is hardly discriminated from a non-fire state before can be detected speedily.
|
