What is the primary purpose of a smoke detector?

The primary purpose of a smoke detector is to alert occupants of smoke or fire. This vital function is critical for ensuring the safety of individuals within a building. Smoke detectors use various technologies, such as ionization or photoelectric sensors, to detect the presence of smoke particles in the air. Upon detection, the device emits an audible alarm, giving occupants the necessary warning to evacuate the premises and seek safety. This early warning system plays a crucial role in preventing injuries and fatalities caused by fire, as it allows individuals to respond swiftly during an emergency. The other options do not align with the fundamental function of a smoke detector, as they pertain to different systems or purposes unrelated to fire safety.