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Do not remove or puncture the white filter in the bottom of the filter cartridge.
If this filter becomes damaged, discard the filter cartridge.
CAUTION:
and replacing it. Replacement dust filter cartridges are available as Part No. DF-105. The dust-
stopper should be inserted between the dust and water-block filter and the probe or water-stopper.
Flue Gas Filter
This filter is screwed, finger-tight, between the telescoping metal flue probe and the dust
and water-block filter. It must be used for CO measurements in flue gas and may also be used for
CO measurements in ambient air. The beads in the filter cartridge should be replaced when about
90% of the material has changed color from purple to brown or when it becomes blocked by soot
or water. Filter beads for refilling approximately 50 cartridges are available as Part No. PR-050.
Replacement flue gas filters are available as Part No. FF-005 (package of 5 filters).
To refill the filter cartridge, remove the threaded top and pour out the spent filter material.
Retrieve the plastic retainer disk from the spent filter material. Fill the cartridge with fresh filter
material up to the bottom of threads, place the plastic retainer disk flat on top, and screw the top
finger tight. Check the seal by carrying out a block test with the detector.
Heavy Hydrocarbon Filter
A heavy hydrocarbon filter, filled with activated carbon, can be used with the standard
probe or the bar hole probe on a one-time-only basis. Activated carbon adsorbs gasoline and other
heavy hydrocarbons (for example, propane or butane) which interfere with methane detection. In
order to keep the filter material from adsorbing hydrocarbons prior to use, the filter is fitted with
plastic end caps which must be removed just before use. The filter should be either discarded after
use or refilled with activated carbon and recapped with the plastic end caps. This filter is designed
to be screwed finger-tight between the probe and the dust and water-block filter. Activated carbon
for refilling approximately 50 cartridges is available as Part No. HR-050. The refill procedure is
the same as described for the flue gas filter. Heavy hydrocarbon filters are available as Part No.
HF-005 (package of 5 filters).
The heavy hydrocarbon filter can also remove some alcohols and unsaturated hydrocarbons
which can interfere with CO readings. The filter should be discarded or refilled
after each use.