Fire is one of the most serious dangers we face, so reliable and effective fire protection is essential. West London Security offer various types of fire detection technologies for sensing and detecting the presence of smoke, heat or other early indications of fire.

Manual

The best fire detector is a human being - and WLS offer a wide choice of manual call points for internal and external use. These are normally mounted at the exit of the protected area.

Automatic

There are three types of automatic fire detectors. Many detectors available on the market offer a combination utilising two of the three types available; these greatly reduce false alarms.

1.Thermal detectors

These detectors respond to increases in temperature. Rate of Rise detectors respond to an acceleration in the level of heat. Fixed temperature detectors respond when the temperature rises above a certain level. Thermal detectors are also used in heat probes, which detect sudden rises in temperature inside a boiler, an oven, or other industrial processes.

2.Ionisation detectors

Ionization detectors respond to smoke and gas particles from a flaming fire. They use a non-harmful radio-active source (Americium 241) to transform the air inside them into a conductor of electric current and a small current passes through the ionised air. When a fire starts, atomic particles become ionised by the heat of combustion; when these particles enter the detector, they impede the flow of the current. The alarm is triggered when the current gets too low.

3.Photoelectric detectors

These detectors respond to smoke from a smouldering fire. They consist of a lamp which directs a narrow beam of light across the detection chamber. Next to this light source, but hidden from the beam, is a light-sensitive photocell. When smoke enters the detection chamber, it scatters the light beam, reflecting it in all directions. Some of this reflected light is bounced back to the photocell which, at a preset level, triggers the alarm. Photoelectric detectors can also detect interference in two beams of light which cross the detection chamber; the principle is the same.