What is the operating principle of the spot detector sensor in a fire detection system?

bimetallic thermoswitch that closed when heated to a high temperature

Explanation:

solution

operating principle of the spot detector sensor is bimetallic thermoswitch that closed when heated to a high temperature

A thermal switch system is one or more light energized power system and thermal switch that control operation of the light

and thermal switch is heat sensitive unit that is complete electrical circuit at some certain temperature

these are connected in parallel with each other

so here correct answer is bimetallic thermoswitch that closed when heated to a high temperature