LumaSense Technologies INNOVA 1412i - Manual (Page 132)

Chapter 11
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BE6025-15 1412i Photoacoustic Gas Monitor LumaSense Technologies A/S
Page 132 of 202
Fig.11.8 The parts of the external air-filtration unit UD 5023
Moisten a cotton bud with pure acetone and use it to clean the
surfaces of the unit, the retaining disc and the coarse air-filter. Refer
to Fig.11.8. Place the stub-end of the unit downwards, on a clean,
dry surface; the coarse air-filter, with its screw-end downwards on a
clean, dry surface and rest the retaining disc against it.
Caution: Make sure that no cotton fibres remain on the mesh of the
retaining disc otherwise they could be sucked up into, and block the
measurement system when the analyser is operated.
Notes:
Only proceed to the next step when the acetone has completely
evaporated from the cleaned surfaces.
Each of the fine filter-papers DS 0759 are packed between two
pieces of packing paper. The fine filter-paper is always white in
colour.
Hold the stub-end of the unit between your thumb and fingers. Lift
the retaining disc with the tweezers and place it back into position in
the unit. Refer to Fig.11.8 .
Remove a new fine filter-paper from its packaging using the
tweezers. Hold it by its edge. Carefully place the filter-paper over the
top of the retaining disc so that it is held in position by the small “lip”
on the rim of the unit.
Screw the coarse air-filter over the end of the external air-filtration
unit. Make sure that the fine filter-paper remains in its correct
position directly over the retaining disc.
11.2 Cleaning the Filter in the Ventilation Unit
A small ventilation unit is mounted on the back panel of the Monitor
(see in Fig.11.9 ). The ventilating fan in this unit circulates air
through the Monitor to keep it cool. To ensure that the air being
drawn into the Monitor is free of particles a filter pad is placed be-
tween the fan and grid which covers it. This filter needs to be