How Does a Photoelectric Smoke Detector Work?
A photoelectric smoke detector is comprised of a few simple parts; a T-shaped chamber with a small light bulb or LED aimed toward the top of the T, a lens to focus the light into a concentrated beam, and a photodiode which detects the presence of the beam. When functioning normally the LED emits light in a steady beam at the photodiode. The sides of the T-shaped chamber are vented and open. As smoke rises, it would rise up to the smoke detector and seeps into the vents of the chamber. By doing so the smoke obscures the light, preventing it from striking the photodiode. When this happens the alarm is triggered. How Does an Ionization Smoke Detector Work? An ionization smoke detector is cheaper and more effective than a photoelectric smoke detector, but some people are bothered by keeping them in their homes as the detectors make use of a radioactive substance. This substance is called americium and is not considered to be dangerous given the infinitesimally small amount used, though som
