There are many brands of smoke detector on the market, but they all fall under two basic types— ionization chamber detectors and photoelectric detectors. Both types have two basic parts: a sensor to sense the smoke and a very loud electronic horn to alert people. They come either battery-powered or hardwired.
Ionization detectors use a radioactive source that produces electrically charged molecules (ions). This sets up an electrical current within the detector chamber. When smoke enters the chamber, it attaches to the ions and reduces the flow of electrical current, which sets off the alarm. Ionization detectors are better at detecting the smaller amounts of smoke produced by fast, flaming fires.
Photoelectric detectors use an optical detector sensor (a photo beam) and go off when smoke from a smoldering fire is dense enough to deflect that beam of light.Because homeowners cannot predict the type of fire that might start, a combination smoke detector—called a dual-sensor smoke alarm—can be a wise choice.
Battery-powered detectors are easier to install and will continue to work during a power failure.
The batteries in battery-powered detectors last approximately one year. When the battery needs replacing, the detector will chirp every minute or so to indicate that the batteries are expiring.
Hardwired detectors operate on a household electrical current and operate as long as the house has power. Plug-in units need to be located near an electrical outlet where they will not be unplugged or turned off by a wall switch. Hardwired smoke detectors should not be plugged in with the use of an extension cord and should always utilize the hold-in clips provided to prevent accidental plug removal from the outlet. Hardwired detectors typically have a battery as a power-supply backup in case of a power failure.
More about smoke detectors:
Get a Pre-Screened Fire Prevention and Protection Contractor
Copyright. All rights reserved.
