Certified Fire Inspector II Practice Test 2025 - Free Practice Questions and Study Guide for Fire Inspectors

Heat detectors are designed to activate when the temperature reaches a certain threshold, indicating a potential fire hazard. The correct temperature range for heat detector activation is between 135°F and 190°F. This range is effective because it allows the detector to respond to significant temperature changes associated with fire while minimizing nuisance alarms due to normal temperature fluctuations in the environment.

Heat detectors serve as important safety devices in fire protection systems. They operate based on the principle that the temperature increases significantly when a fire occurs. By being calibrated to activate in the 135°F to 190°F range, they can effectively detect fires in their early stages, allowing time for evacuation and response.

The other ranges do not align with the standard operational thresholds for common heat detectors; they either activate too early, which could lead to frequent false alarms, or too late, missing critical early fire cues.