The FWC-FSLC-HEAT Heat sensor incorporates a highly linear thermistor circuit, with the thermistor mounted externally. The specially designed cover protects the thermistor while allowing maximum air flow. The thermistor circuit produces a voltage proportional to temperature which is scaled and transmitted as a digitally encoded value to the control panel. When the ambient temperature exceeds a pre-programmed threshold (fixed temperature), the sensor transmits an interrupt to the control panel indicating a fire alarm. The fire alarm control panel can adjust the sensor threshold for different Standard's requirements. Up to 127 devices are permitted on each loop. A sensor address can be set by a hand-held programming unit. The sensor mounts to an electronics free base and incorporates a locking mechanism for a secure installation. The base provides mounting slots, terminals for field wiring, and a third contact for a remote indicator / LED. The sensor incorporates dual LEDs for easy viewing of sensor status.