What is the function of a heat detector in a fire suppression system?

A heat detector serves a critical role in fire suppression systems by detecting increases in temperature that may signify a fire. These devices are particularly important in environments where smoke detectors might be less effective, such as areas with high dust, steam, or vapor levels.

When the heat detector senses a rise in temperature that exceeds a predetermined threshold, it activates the fire alarm system. This alert allows for a rapid response to the potential fire, which may include triggering suppression systems like sprinklers or notifying emergency services. Heat detectors can be categorized into fixed-temperature models, which activate at a set temperature, and rate-of-rise models, which respond when the temperature increases rapidly over a short period.

In contrast, other options do not accurately represent the main purpose of heat detectors. For example, while smoke detection is crucial, it is not the function of a heat detector. The roles related to measuring humidity or monitoring air quality do not align with the primary objective of detecting heat to indicate fire hazards. Thus, the answer explains that the function of heat detectors is essential for early fire detection and response, making option B the correct choice.