How do smoke detectors function to detect smoke?

Smoke detectors primarily function by utilizing either ionization or photoelectric technology to detect smoke particles. In the case of ionization smoke detectors, they contain a small amount of radioactive material that ionizes the air in a sensing chamber, creating a current. When smoke enters this chamber, it disrupts the ionization process, leading to a decrease in current that triggers the alarm.

On the other hand, photoelectric smoke detectors work by emitting a light source into a sensing chamber. When smoke particles enter the chamber, they scatter the light, redirecting some of it to a sensor that triggers the alarm.

Both of these methods effectively detect the presence of smoke through changes in the environment within the detector, rather than through temperature changes, carbon monoxide levels, or sound waves, which are not primary mechanisms for smoke detection.