What device includes a light source and a photoelectric sensor to detect smoke?

The photoelectric smoke detector is designed to utilize a light source in conjunction with a photoelectric sensor to detect smoke. This device operates on the principle of light scattering. Inside the detector, a light beam is directed into a sensing chamber. When smoke enters this chamber, it interferes with the light beam, scattering the light and causing the photoelectric sensor to detect a change in light intensity. Once the sensor detects the scattered light, it triggers the alarm, indicating the presence of smoke.

This technology is particularly effective in detecting smoldering fires that produce a significant amount of smoke before flames occur, making it a valuable safety device in both residential and commercial settings. Its specificity to smoke detection distinguishes it from other devices like ionic smoke detectors, which use a different mechanism involving ionization, or heat detectors, which respond only to changes in temperature rather than the presence of smoke. Manual pull stations, on the other hand, are activated by individuals in case of emergencies but do not detect smoke on their own.