How Do Smoke Detectors Work?

10/7/2019 (Permalink)

Smoke Detector

October 6 – October 12 is Fire Prevention Week and smoke detectors play a huge role in preventing loss and injury with property fires. SERVPRO of Edgewater/Deale-Churchton/Lothian wants to know how smoke detectors really work. So, we’ve done some research.

First, there are 2 common types of smoke detectors: ionization detectors and photoelectric detectors. Most smoke alarms use these types of detection as well as heat to warn of a fire.

Ionization Smoke Detectors have a chamber and a source of ionizing radiation. If smoke enters the ionization chamber, the smoke particles attach to the ions and neutralize them, so they do not reach the plate. The drop in current between the plates triggers the alarm.

Photoelectric Detectors contain a T-shaped chamber with a light-emitting diode (LED) that shoots a beam of light across the horizontal bar of the T. When smoke blocks the light beam, the reduction in light reaching a photocell triggers the alarm.

So, which type of smoke detector do you need for your property? Both ionization and photoelectric detectors are effective smoke sensors. Both types of smoke detectors must pass the same test to be certified. Ionization detectors respond more quickly to flaming fires with smaller combustion particles; photoelectric detectors respond more quickly to smoldering fires.

To learn more about the type of smoke detectors your property needs, refer to Maryland Law.