Fire Alarm

One of the greatest innovations in fire safety has been the development of the home fire alarm. This inexpensive, compact and easy to install device has saved many lives over the years. Installation of alarms in the home is strongly recommended by fire departments, and has even been made mandatory for new homes in some countries.

The typical fire alarm has a white plastic case that is one inch high and several inches in diameter. There is usually a test button and small light on the front and a bracket attached to the back. Most alarms have a cover that separated from the body or one that swings open on a hinge. Inside the alarm, there is a circuit board with a detection chamber, siren and battery holder attached to it.

A fire alarm can be installed with screws, glue or double sided tape. It should be mounted in the center of the ceiling or high up on a wall, and should not be fitted any lower as smoke rises. It should not be installed within fifteen feet of the kitchen to prevent false alarms from cooking smoke. As always, first check the location with a stud finder before drilling to find any wires or pipes in the way.

When smoke or particles from a fire enter the detection chamber, it causes a change in a steady signal. The circuitry detects this change and activates the siren, stopping it only when the detection chamber is empty and the regular signal has been restored. Optical alarms use a light beam and detector, while ionizing alarms use a small radioactive source. There is no risk from this source because the radiation is weak and it only has a short range. Smoke is detected faster with an optical alarm but particles are detected faster by an ionizing alarm. Some alarms have both types, as well as a sensor that detects carbon monoxide.

Most fire alarms operate on battery power, with small alkaline batteries being the most common type used. Even alarms with fixed wiring often have a rechargeable battery as a backup power source. Most alarm batteries last a few months before needing to be changed, but some may need replacing after only a few weeks if the siren has been sounding for a long time.

A fire alarm emits short beeps as its battery begins to fail. The alarm will continue beeping for several days until the battery is completely flat. However, it should be replaced before this happens, as it may not have enough power to keep the siren going for very long. Several spare batteries should always be kept as replacements rather than have the alarm not working for any length of time.

Replacing the battery in a fire alarm is a simple task, but some people may require assistance to get the alarm off the roof. An alarm is removed from its bracket by rotating it slightly and pulling downwards, similar to how a light bulb is removed. The cover can then be opened and the old battery removed. There may be a spring-loaded tab that prevents the cover being replaced when there is no battery in the holder, and this tab needs to be pushed down before the new battery is inserted. Once the cover has been replaced, the alarm should be tested by pushing the test button.

A fire alarm should be installed in as many rooms as possible because house fires spread very quickly so every second counts. Always change the batteries when needed and replace the alarms themselves every ten years. Finally, make sure everyone in the house knows what the alarms sound like and what they should do in the event of a fire.

This Fire Alarm Review is Written/Updated on Jul 24th, 2009 and filed under Home Automation. Both comments and pings are currently closed.

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