Det-Tronics Eagle Quantum 95-8470-05, Инструкция по эксплуатации

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The UV/IR detector does not respond to arc welding
beyond 10 feet from the detector. However, a UV only
signal will be generated in response to the intense UV
radiation generated by the arc welding, and at
distances
closer than 10 feet the heated metal from the
welding can become a false alarm source for the IR
sensor.
FACTORS INHIBITING DETECTOR RESPONSE
Windows
Glass and Plexiglas windows significantly attenuate
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 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 or IR absorbing gases or vapors must not
be allowed to accumulate between the detector and the
protected hazard. See Table V-1 for a list of these
substances.
Smoke
Smoke will absorb radiation. If accumulations 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 and/or IR
radiation include, but are certainly not limited to, the
following:
Silicones
Oils and greases
Ice buildup
Dust and dirt buildup
Paint overspray.
UV/IR DETECTOR POSITIONING
IMPORTANT
Detectors should not be positioned so that their
cone of vision can scan the horizon. Rather, they
should be directed down over the designated
hazardous area to reduce the likelihood of picking
up radiation from distant sources. See Figure 1.
Detectors should be located in positions best suited for
covering the area to be protected. Whenever practical,
they should be placed where they will be easily
accessible for cleaning and other periodic servicing.
Particular attention should also be paid to potential false
alarm sources within the cone of vision of the detector,
such as distant arc welding, or the rotating blades of a
fan or surface vibration of an IR source, which could
allow a flickering IR signal to reach the detector. Rain
or ice can absorb radiation, which can reduce the
capability of the detector. For outdoor applications, aim
the detector downward to minimize the buildup of water
or ice on the detector viewing windows and to prevent
the cone of vision from scanning the horizon. This
minimizes response to distant radiation sources outside
the protected area.
GAS DETECTOR POSITIONING
The sensor must be properly located to enable it to
provide maximum protection. The formula for
determining the most effective number and placement
of sensors varies depending on the conditions at the job
site. The individual performing the installation must rely
on experience and common sense to determine the
quantity of sensors and the best sensor locations to
adequately protect the area.
The following factors should be considered for every
installation:
1. What kind of gas is to be detected? If it is lighter
than air (acetylene, hydrogen, methane, etc.), place
the sensor above the potential source. Place the
sensor close to the floor for gases that are heavier
than air (benzene, butane, butylene, propane,
hexane, pentane, etc.) or for vapors resulting from
flammable liquid spills. However, note that air
currents can cause a gas that is heavier than air to
rise. In addition, if the gas is hotter than ambient
air, it could also rise.
2. How rapidly will the gas diffuse into the air? Select
a location for the sensor as close as practical to the
anticipated source of a gas leak.
V-3 95-8470