Smoke Detector

fire safety · home protection · clever gadgets · safety

Spots smoke fast. Smoke detectors use special sensors to catch smoke in the air, either by shining a light beam through the smoke or by sensing tiny particles with electrical charges. When they detect smoke, they beep loudly to alert you and everyone nearby.

Disk-shaped device. Most smoke detectors are flat, round plastic discs about the size of a small plate, roughly 5 inches across and 1 inch thick. You usually see them stuck on ceilings or walls in homes and buildings.

Two sensing methods. Some smoke detectors use optical sensors that shine a light and watch for smoke to block it, while others use ionization to detect smoke particles electrically. Many modern detectors use both methods to catch different types of fires.

Connected to systems. In big office buildings, shopping malls, and factories, smoke detectors aren't just standalone alarms. They're all linked to a central fire alarm system that alerts firefighters and building managers when smoke is detected anywhere.