A heat detector detects smoke by which mechanism?

A heat detector detects smoke by which mechanism?

• A. Change in temperature
• B. Detection of smoke particles
• C. Sound level increase
• D. Chemical reaction

Answer: (A)

Heat detectors respond to changes in temperature, not to smoke itself. They come in two main flavors: fixed-temperature devices that trip when the surrounding air reaches a set temperature, and rate-of-rise devices that trigger when the temperature climbs quickly over a short period. When a fire heats the environment, this thermal change is what activates the detector and starts the alarm. This is why the mechanism is described as a change in temperature. It’s different from smoke detectors, which detect smoke particles, or from sensors that rely on sound levels or chemical reactions. In areas where smoke alarms could cause nuisance alarms, heat detectors are useful because they focus on heat buildup rather than the presence of smoke.

Heat detectors respond to changes in temperature, not to smoke itself. They come in two main flavors: fixed-temperature devices that trip when the surrounding air reaches a set temperature, and rate-of-rise devices that trigger when the temperature climbs quickly over a short period. When a fire heats the environment, this thermal change is what activates the detector and starts the alarm. This is why the mechanism is described as a change in temperature. It’s different from smoke detectors, which detect smoke particles, or from sensors that rely on sound levels or chemical reactions. In areas where smoke alarms could cause nuisance alarms, heat detectors are useful because they focus on heat buildup rather than the presence of smoke.