Which type of detector uses the light scattering principle?

The photoelectric smoke detector operates on the light scattering principle, making it highly effective in detecting smoke from smoldering fires. This type of detector contains a light source (usually a light-emitting diode) and a photosensitive sensor. When smoke particles enter the detection chamber, they scatter the light emitted by the diode. As the light scatters, it reaches the photosensitive sensor, which then triggers the alarm.

This principle is particularly advantageous because photoelectric smoke detectors are more likely to respond to the larger smoke particles produced by slow, smoldering fires, which might not generate the rapid heat or visible flames that other detector types are designed to detect. Consequently, they can provide early warnings for certain types of fires, enhancing overall safety.

Other types of detectors, such as ionization smoke detectors, rely on the ionization of air particles rather than light scattering. Thermal smoke detectors trigger alarms based on temperature changes rather than smoke presence. Carbon monoxide detectors are separate and specifically designed to detect the presence of carbon monoxide gas instead of smoke particles.