A burglar alarm or fire alarm device that detects a preset high temperature or a rapid rate-of-rise (ror) in temperature. heat detectors can be either electrical or mechanical in operation. the most common types are thermocouple and electro-pneumatic, both of which respond to changes in ambient temperature. if the ambient temperature rises above a predetermined threshold, then an alarm signal is triggered. heat detectors are better than smoke detectors for areas where smoke would normally be found such as a kitchen or smoking lounge, since they do not produce as many false alarms.
