fire detector / smoke

The Gamewell-FCI projected beam
smoke detector offers vital fire detection
in applications where spot-type
detectors are not adequate. This
model is four-wire, 24 VDC and includes
both the transmitter and receiver.
Features include automatic
compensation for signal drift or dirty
lens, alignment LEDs for simple setup
and adjustment and three field-adjustable
sensitivity settings. This detector
provides linear protection from 30 to
320 feet (9.144 to 97.539 m).
Operation
The infrared signal is sent from the
transmitter via an optical system. At
320 feet (97.536 m), the diameter of
this infrared signal is approximately 9.5 feet (2.896 m). The wide angle beam
arrangement simplifies alignment and increases stability.
It is important that the projected beam smoke detector is positioned correctly to
minimize the detection time. Experiments have shown that smoke from a fire
does not rise directly upwards. The smoke fans out in a “mushroom” shape due
to air currents and heat-layering effects.
A fire alarm condition occurs when the smoke obscures the infrared beam. The
time to detect a fire condition depends on the location of the smoke beam within
the premises, the volume of smoke produced, the construction of the roof, and
ventilation considerations.