Most fires occur at night when people are sleeping. A smoke detector can alert you when there is a fire, in time to save your life.
Smoke detectors work by sensing rising smoke from a fire and sounding an alarm.
Photoelectric uses a photoelectric bulb that sends forth a beam of light. When smoke enters, light from the beam is reflected from smoke particles into a photocell and the alarm is triggered. Ionization Chamber contains a small, safe radiation chamber source that produces electrically charged air molecules called ions. When smoke enters the chamber, it causes a change in the flow of ions, triggering the alarm. In a Multi-level home, a detector is needed on each level.