Final answer:
Rate-of-rise detectors are a type of heat detector that automatically reset after being triggered. They detect rapid increases in temperature and reset themselves once the temperature stabilizes. An example of a heat detector that automatically resets is a thermal switch used in appliances.
Step-by-step explanation:
Heat detectors are devices used to detect and indicate the presence of fire or high temperatures. There are two main types of heat detectors: fixed temperature detectors and rate-of-rise detectors. While fixed temperature detectors require manual reset after being triggered, rate-of-rise detectors automatically reset.
Rate-of-rise detectors are designed to detect rapid increases in temperature. They have two heat-sensitive elements: one that measures the ambient temperature and another that measures the rate of temperature rise. When the rate of rise exceeds a predetermined threshold, the detector triggers an alarm. Once the detector cools down and the temperature stabilizes, it automatically resets itself.
An example of a heat detector that automatically resets is a thermal switch used in appliances like hair dryers and irons. These switches are designed to break the electrical circuit when the temperature reaches a certain threshold and automatically reset when the temperature falls back within a safe range.