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GENERAL APPLICATION
INFORMATION
RESPONSE CHARACTERISTICS
Response is dependent on distance, type of fuel,
temperature of the fuel, and time required for the fire to
come to equilibrium. As with all fire tests, results must be
interpreted according to an individual application.
See Appendix A for fire test results.
WELDING
Electric arc welding is a source of intense ultraviolet
radiation. UV radiation from arc welding readily scatters
and can deflect across significant distances, even when
direct obstructions exist. Any open door or window can
allow nuisance UV radiation from arc welding to enter an
enclosed area.
It is recommended that the system be bypassed during
welding operations in situations where the possibility of a
false alarm cannot be tolerated. Gas welding mandates
system bypass, since the gas torch is an actual fire.
ARTIFICIAL LIGHTING
The X2200 should not be located within 3 feet of artificial
lights. Excess heating of the detector could occur due to
heat radiating from the lights.
EMI/RFI INTERFERENCE
The X2200 is resistant to interference by EMI and RFI,
and is EMC Directive compliant and CE Marked. It will
not respond to a 5 watt walkie-talkie at distances greater
than 1 foot.
FALSE ALARM SOURCES
The UV sensor is solar blind to the ultraviolet component
of solar radiation. However, it will respond to sources of
UV besides fire, such as electric arc welding, lightning,
high voltage corona, x-rays and gamma radiation.
8.3
FACTORS INHIBITING DETECTOR RESPONSE
Windows
Glass and Plexiglas windows significantly attenuate UV
radiation and must not be located between the detector
and a potential flame source. If the window cannot be
eliminated or the detector location changed, contact
Detector Electronics for recommendations regarding
window materials that will not attenuate UV radiation.
Obstructions
Radiation must be able to reach the detector in order
for it to respond. Care must be taken to keep physical
obstructions out of the line of view of the detector. In
addition, UV absorbing gases or vapors must not
be allowed to accumulate between the detector and
the protected hazard. See Table 3 for a list of these
substances.
Smoke
Smoke will absorb UV radiation.
of dense smoke can be expected to precede the
presence of a flame, then detectors that are used
in enclosed areas should be mounted on the wall
approximately 3 feet (1 meter) from the ceiling where
the accumulation of smoke is reduced.
Detector Viewing Windows
It is important to keep the detector viewing windows as
free of contaminants as possible in order to maintain
maximum sensitivity. Commonly encountered substances
that can significantly attenuate UV radiation include, but
are certainly not limited to, the following:
Silicones
Oils and greases
Dust and dirt buildup
Paint overspray
4
If accumulations
95-8549
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