Linear Heat Detection (LHD) uses a wire or cable instead of a thermostat to detect heat from fire. There are many customizable options when it comes to installation, making it a versatile and effective means of heat detection in many applications.
Linear Heat Detection (LHD) is a continuous heat detector designed to detect heat along the length of a sensor cable. This sensor cable is made up of two conductors, both insulated by heat sensitive polymers.
The heat sensitive polymer is protected by an outer jacket. Beneath this jacket and heat sensitive polymer coating is a pair of steel conductors. When the ambient temperature meets or exceeds the detector’s fixed temperature, the polymer melts. As it melts, the steel conductors make contact and initiate an electrical short that then sends a signal to the fire alarm panel of an alarm condition.

