What type of fire detection system operates on the principle of rate-of-temperature rise?

The thermocouple system is one that operates on the principle of rate-of-temperature rise. This system measures the change in temperature over a specific period of time. When there is a fire, the temperature in the environment increases rapidly. The thermocouple detects this rise and triggers an alarm or activates suppression systems depending on the design of the fire detection system.

This method allows for quick identification of potential fire conditions by monitoring how quickly the temperature increases, distinguishing it from other systems that may rely on constant temperature thresholds or different detection mechanisms. Because of its ability to provide an early warning of a fire based on the rapid increase in heat, the thermocouple system is effective in aerospace and powerplant applications where early detection can prevent extensive damage and enhance safety measures.

The other systems mentioned, while potentially effective in their own right, utilize different detection methods that do not focus specifically on measuring the rate of temperature change, therefore, they do not match the criteria established in the question.