What is the primary role of a heat detector in an alarm system?

The primary role of a heat detector in an alarm system is to detect changes in temperature. Unlike smoke detectors, which are designed to sense the presence of smoke particles often associated with fire, heat detectors focus on monitoring temperature changes that occur when a fire starts.

Heat detectors are typically used in environments where smoke detectors may not be effective or could produce false alarms, such as kitchens or garages. When the temperature reaches a pre-set threshold, the heat detector activates, signaling that a potential fire condition might be present. This capability is crucial in early detection and helps in fire response planning.

Other options do not align with the primary function of a heat detector. For instance, signaling an intrusion pertains more to security systems rather than fire detection. Additionally, while smoke detection is vital in fire safety, it is not the function of a heat detector. Triggering an audio alarm is a response mechanism but does not define the core function of the heat detector in monitoring environmental conditions.