Beam Detectors Installation process
Beam
Detectors are a well-established product available in the fire alarm
industry. Commonly beam detectors are used to provide automatic fire
detection in large open spaces, such as warehouses, airports and
factories.
A
beam detector works by having a transmitter and receiver. The transmitter
part of the beam detector fires out an infrared beam which is then received by
the receiver. The beam detector is designed to set a fire alarm system
into alarm when a pre-set level of smoke obscures the infrared
beam. Beam detectors are available in two types, these are reflective beam detectors and point to point type beam detectors.
A reflective beam detector works by firing the infrared beam from a transmitter
at a reflector positioned at the other end of the area being covered by
the beam detector, the beam is then reflected back towards the beam detector
unit which also has a receiver built into the enclosure. A point to point
beam detector operates by having a dedicated transmitter located at one side of
the area being covered by the beam detector and then having a dedicated
receiver at the other end of the protected area.
One
major advantage of beam detectors is that they can be located a much greater
heights than standard point detectors. The maximum mointing height
of a point detector is 10.5 metres where as BS5839 recommends that beam
detectors can be mounted up to a height of 25 metres. Another advantage
of a beam detector is that one beam detector can provide automatic fire
detection for an area which would require several standard point detectors,
which means that using beam detectors can be much more cost effective than
using standard point detectors.
The Siting of Beam Detectors
- Beam
Detectors can be used at heights of up to 25 metres
- For apex
ceilings extended coverage can be achieved by 1% for each degree of angle
- Beam
Detectors should be positioned within 600mm of the highest point of the
ceiling
- Ceiling
beams close to walls (500mm) or temporary obstructions should be avoided
- Transmitters
& Receivers should be mounted on solid surfaces which are not effected
by wind or natural temperature changes
- Additional
units may be included in atria to detect at lower levels, to counter
statification effect.