In general, the temperature inside the cable is two elastic steel wire, each wire is covered with a layer of temperature and insulation of the material, the normal monitoring of the state, the two wires are in an insulated state, when the ambient temperature rises to the expected operating temperature Time, the temperature-sensitive materials will be broken, the two wires will produce a short circuit, the input module to check the short-circuit signal immediately after the alarm, are "switch" temperature cable.

However, with the expansion of the application of temperature-sensitive cable applications, the industry's technical requirements for the temperature cable has also been deepened, and now there "analog fixed temperature" and "analog differential temperature" temperature cable, the core number But also from the traditional two-core into four-core.

Four-core analog fixed-temperature temperature sensing cable, composed of four core, the temperature changes, the resistance between the four-conductor changes, the resistance changes to set the alarm threshold, the detector issued a fire alarm signal.

Four-core analog differential temperature temperature sensing cable, composed of four core, the temperature changes, the resistance between the four-conductor changes in the resistance rate or change the amount of change to set the alarm threshold, the detector issued a poor Temperature fire or fixed temperature fire alarm signal.