A flame detector is a sensor that detects and responds to the presence of a flame or fire. Its response can vary depending on the system it’s connected to, such as triggering an alarm, shutting off fuel lines (like propane or natural gas), or activating fire suppression systems. In industrial settings like furnaces, flame detectors ensure proper functioning and may disable the ignition system, though often their main role is to notify operators or the control system. Flame detectors are typically faster and more precise than smoke or heat detectors due to their unique detection mechanisms.