HEAT DETECTORS

Heat Detector has the two function of Rise Temperature and Fixed Temperature.Heat Detector contains pair of negative Temperature coefficient thermistors. One thermistor is exposed to the surrounding air and responds quickly to changes in air temperature. The other thermistor is insulated from the surrounding air and responds slowly.When the air temperature increases rapidly, the temperature difference develops between the thermistors. The ratio of the resistance of the thermistors is monitored electronically and a fire alarm is initiated if the ratio exceeds a factory preset level;. This feature illustrates the Rate of Rise function of the Detector.When the air temperature increases slowly, the two thermistors reduced its resistance to a predetermined value, then the fixed resistance will initiate a Fire alarm. This feature illustrate the fixed temperature function of the Detector.