Smoke detectors are one of the most important devices when it comes to fire safety in your home. They are the first thing that will alert you to a fire or smoke in your home, they can be the difference between life in death in a fire because every second counts and it is smoke detectors that can give you the early warning sign. No home should ever be without several smoke alarms,
There are two main types of smoke alarms available on the market today, namely ionization smoke detectors and photoelectric smoke detectors.
Ionization smoke alarms use a very small quantity of radioactive material to ionize air in an ionization chamber. This chamber becomes conductive allowing current to flow between two charged electrodes. When products of combustion enter the chamber such as smoke particles, the conductivity of the air in the chamber is lowered. When the conductivity of the air is lowered to a predetermined level, the alarm will go off.
Photoelectric smoke alarms consist of an LED (light emitting diode) and a light sensitive sensor in a sensing chamber. If products of combustion, like smoke particles are found in the chamber they will cause the light to scatter and stop the light from reaching the sensor, this in turn causes the alarm to sound.
As the two types operate on two different sets of principles, they may respond differently to various conditions
Ionization alarms are better suited for rooms that contain highly combustible items that will create flaming fires. These items would include flammable liquids or newspapers. Photoelectric devices would be better suited for bedrooms, living rooms and kitchens, as these rooms often contain large pieces of furniture, such as mattresses, armchairs or sofas which would burn more slowly and create smoldering smoke rather than hot flames.
Each of the types of alarms have been tested and certified by fire safety authorities to be used within the home and as each react slightly better to different types of fire it is probably best to have a selection of both types located around your home.
No comments:
Post a Comment