The Signature Series model SIGA2-HRS Intelligent FixedTemperature and Rate-of-Rise Heat Detector is an intelligent device that contains a rate-of-rise and fixed-temperature heat sensor to detect fire. The heat sensor monitors the temperature of the surrounding air and the detector analyzes the data from the sensor to determine whether to initiate an alarm. The rate-of-rise heat function quickly detects a fast, flaming fire. The fixed-temperature heat function detects fire when the air temperature near the detector exceeds the alarm point.