Process

• Photoelectric smoke detectors pick up on the presence of smoke through a process that uses a light source. The light is aimed into the unit's sensing chamber. The steady beam gets broken when smoke drifts inside the detector, setting off an audible alarm that alerts household occupants to the fire.
  
  

Strength

• The main strength of a photoelectric smoke detector is its ability to detect smoldering fires before they break out into active flames. These detectors are effective in bedrooms, living rooms and family rooms because of bedding, furniture and other materials that could smolder for a long time because they give an early warning before fire takes hold of the area.
  
  

Alternative

• Ionization smoke detectors are an alternative to photoelectric models. They contain radioactive material positioned between two electrically charged plates. The air inside the chamber is ionized, and current flows continually between the plates. Smoke interrupts the flow when it gets inside the detector, setting off the alarm. Ionization models are best at alerting you to blazing fires, and they are the most commonly used household models, according to the Fire Safety Council.
  
  

Maintenance

• Photoelectric smoke alarms need regular maintenance to work properly. Vacuum the detector regularly to remove dirt and dust that could block smoke from getting into the light chamber, the Kentucky Injury Prevention and Research Center advises. Never paint over it as this also blocks the openings. Cover the alarm with plastic if you do dust-raising work, like drywall installation, in the room where it is located. Change the batteries at least once a year, and tie the changing to a special date, like the start of Daylight Savings Time, so you can remember to change them. Photoelectric detectors do not last forever, so the Fire Marshall's Public Safety Council recommends replacing them after 10 years of service.
  
  

Considerations

• You get the most protection if you use both photoelectric and ionization smoke detectors since each is geared to detect a specific fire type more effectively. You can purchase photoelectric models for rooms with furniture, mattresses and other household goods prone to smoldering and ionization models for areas where flammables are stored. Manufacturers also sell combination smoke detectors that combine both technologies into a single unit.