Which detector type uses a light source and photocell to detect smoke by scattering light within a sensing chamber?

Which detector type uses a light source and photocell to detect smoke by scattering light within a sensing chamber?

• A. Ionization Smoke Detector
• B. Photoelectric Smoke Detector
• C. Smoke Detector
• D. Heat Detector

Answer: (B)

Photoelectric detectors work by using a light source and a photocell inside a sensing chamber. When smoke enters the chamber, the smoke particles scatter the light, and some of that scattered light is directed toward the photocell, triggering the alarm. This light-scattering principle makes them especially good at detecting smoldering, smoky fires. Ionization detectors, by contrast, use a radioactive source to ionize air and detect changes in current, not light. Heat detectors respond to high temperatures, not smoke. So the description of a light source and photocell sensing smoke via scattered light points to the photoelectric smoke detector.

Photoelectric detectors work by using a light source and a photocell inside a sensing chamber. When smoke enters the chamber, the smoke particles scatter the light, and some of that scattered light is directed toward the photocell, triggering the alarm. This light-scattering principle makes them especially good at detecting smoldering, smoky fires. Ionization detectors, by contrast, use a radioactive source to ionize air and detect changes in current, not light. Heat detectors respond to high temperatures, not smoke. So the description of a light source and photocell sensing smoke via scattered light points to the photoelectric smoke detector.