What is a defining feature of photoelectric smoke detectors?

A defining feature of photoelectric smoke detectors is that they use a light source and a receiver to detect smoke. This type of detector operates on the principle of light scattering. When smoke enters the chamber of the detector, it scatters the light from the source, which is typically a light-emitting diode (LED). The receiver detects this scattered light and activates the alarm.

This method is particularly effective for detecting larger smoke particles, which are often produced by smoldering fires. As a result, photoelectric detectors tend to respond more quickly to slow-burning fires than other types of smoke detectors, such as ionization detectors that rely on a different detection method. The design and functionality centered around the light source and receiver make this feature essential for the operation of photoelectric smoke detectors.