Smoke Detectors: How Do They Work?

How Smoke Detectors Work

Particles from combustion, ionization, and photoelectric effects are all used in smoke detectors. Smoke detectors are designed to sense particles or changes in the environment caused by smoke. There are two main types of smoke detectors: ionization smoke detectors and photoelectric smoke detectors.

Ionization Smoke Detectors

Ionization smoke detectors use americium-241 to ionize air and detect smoke particles disrupting the ion flow, which triggers the alarm. When smoke enters the chamber, it disrupts the flow of ions, causing the alarm to go off. These detectors are more sensitive to flaming fires that produce small particles.

Photoelectric Smoke Detectors

Photoelectric smoke detectors use a light beam that, if scattered by smoke particles, triggers the alarm. These detectors are more sensitive to smoldering fires that produce larger particles. When smoke enters the chamber, it scatters the light beam, leading to the alarm being activated.

Both types of smoke detectors are effective in detecting different kinds of smoke generated by various types of fires. By understanding how smoke detectors work, we can better appreciate their importance in keeping us safe from potential fire hazards.