RKI Instruments GX-2003 Manual - Manual (Page 18)

11 • Instrument Description GX-2003 Operator’s Manual
CO Filter
The CO filter is located in the flow chamber directly over the CO
sensor. It is a red and black plastic ring which contains two charcoal
filter disks, two H
2
S removal filter disks, and a thin white plastic sheet
with a hole in the middle on each side to support the filter disks. The
charcoal filter disks are black, have a woven texture, and are
impregnated with an H
2
S absorbing material. The red side of the CO
filter snaps into a threaded plastic filter retainer which screws into the
flow chamber over the CO sensor.
The CO sensor will respond if exposed to H
2
S and certain
hydrocarbon gases. The charcoal filter disks scrub these gases out of
the sample to avoid false CO readings. The H
2
S filter disks are used to
extend the H
2
S absorbing life of the charcoal disks. If false or elevated
CO readings are noticed, especially in the presence of H
2
S, change the
CO filter.
Inlet Filter Holder
The filter holder is a clear plastic dome shaped piece on the top of the
case. A male quick connect fitting is located on the inlet filter holder.
This is the GX-2003’s inlet fitting. A cotton dust filter is inside the filter
holder. The filter holder may be removed by turning it
counterclockwise and pulling it away from the case. Two flat
membrane disk hydrophobic filters, a wire mesh disk, and a rubber
filter retaining gasket are held in place by the filter holder and are
located in the bottom of the case chamber where the filter holder is
installed.