Carmel Sensors offers the Euro Series Heat Detector that has a moulded fire retardant grade plastic case with fire resistant heat inlets. This Heat Detector has two functions of Rise Temperature and Fixed Temperature Heat. It 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 illustrates the fixed temperature function of the Detector. This alarm is applicable and useful whenever the level of ambient smoke, dust or fumes produced by a process may cause unwanted alarms from smoke Detectors. Carmel Sensors also manufactures fire alarm control panels, Electronic Hooters, Manual call points, Response Indicators, Exit lamps and smoke and heat detectors, duly approved by CBRI / TAC, Motor control centre, etc.