RKI Instruments Gas Tracer - Manual (Page 19)

Gas Tracer Operator’s Manual Instrument Description • 11
WARNING: To prevent ignition of a hazardous atmosphere, batteries
must only be changed or charged in an area known to be
nonhazardous.
Pump
A diaphragm pump inside the Gas Tracer draws the sample to the
sensors. It can draw sample from as far as 50 feet from the
Gas Tracer. The pump is not user serviceable.
CAUTION: Sample hose lengths of more than 50 feet are not recommended
for the Gas Tracer because of flow rate reduction.
Flow Chamber
The flow chamber is on the back of the Gas Tracer and is held in place
by three phillips screws. The flow chamber seals to the rubber sensor
gasket which seals to the sensor faces inside the Gas Tracer and routes
flow from the pump to the sensors to the exhaust port (also a part of
the flow chamber).
Sensors and Filters
The sensors are located underneath the flow chamber and are only
accessible if you remove the flow chamber and the sensor gasket.
An H
2
S removal filter disk is placed into a recess in the sensor gasket
over the %LEL sensor. This filter darkens as it absorbs H
2
S and should
be replaced when it is a dark brown color. Check the condition of this
filter quarterly.
A charcoal filter is placed into a recess in the sensor gasket over the
CO sensor. The charcoal filter is black, has a woven texture, and is
impregnated with an H
2
S absorbing material. The CO sensor will
respond if exposed to H
2
S and certain hydrocarbon gases. The
charcoal filter disk scrubs these gases out of the sample to avoid false
CO readings. If false or elevated CO readings are noticed, especially in
the presence of H
2
S, change the charcoal filter.
NOTE: If you have a Gas Tracer that is intended for CO with H
2
S
response operation, a charcoal filter will not be installed. Do
not install a charcoal filter.