Which component is commonly found in continuous-loop fire detection systems?

In continuous-loop fire detection systems, heat-sensitive cable is the component that plays a crucial role. This type of system continuously monitors temperature changes along a loop of cable that is installed throughout the area needing fire detection. The cable is designed to sense temperature increases due to a fire, triggering an alarm when a certain threshold is exceeded.

The heat-sensitive cable typically consists of a special material that reacts to heat by altering its electrical resistance, leading to a signal indicating the presence of excessive heat. This allows for a quick response to potential fires, helping ensure safety within the monitored area.

Other options, such as thermocouples, are used in different types of temperature measurements but are not part of continuous-loop systems. Smoke detectors and optical sensors are generally employed in point-based detection systems rather than continuous-loop configurations. Thus, the heat-sensitive cable is the correct choice as it directly aligns with the operational principle of continuous-loop fire detection systems.