| 摘要 |
PROBLEM TO BE SOLVED: To differentially sense the heat independent on the directionality of an air flow. SOLUTION: An additional value or a mean value is found from respective temperature differencesΔT1 andΔT2 between respective outputs of two high- temperature detecting parts 18-1 and 18-2 and an output of a low-temperature detecting part 16 so as to sense a differential heat. That is to say, the temperature difference additional value (ΔT1+ΔT2) independent on the direction of the air flow or the temperature difference mean value (ΔT1+ΔT2)/2 is found and, when the value exceeds a prescribed threshold, it is determined to be a fire. |
