Which of the following describes a fixed-temperature heat detector?

A fixed-temperature heat detector is designed to activate when the surrounding air temperature reaches a specific, predetermined level. This method of detection relies on a device that is calibrated to respond to heat at a fixed point, meaning once the temperature exceeds this preset threshold, the detector will trigger an alarm or initiate a response from a fire suppression system.

This type of detector is particularly useful in environments where rapid heat changes might not occur, but where exceeding a certain temperature indicates a fire condition. In contrast to options that involve detecting a rate of temperature change, smoke presence, or require manual intervention, a fixed-temperature heat detector operates automatically when the environmental conditions reach its set point, making it a reliable choice for many applications in fire safety.