Geotech GEM5000 - Page 62

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Page 62 of 127
Operating Manual
OMGEM5KN – Iss. 5.1
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Copyright – Geotechnical Instruments (UK) Ltd
GEM5000
The oxygen sensor is a galvanic cell type and suffers virtually no influence from CO
2
, CO, H
2
S, NO
2
, SO
2
or H
2
,
unlike many other types of oxygen cell.
The infrared sensors will not be ‘poisoned’ by other hydrocarbons and will revert to normal operation as soon as
the gas sample has been ‘purged’.
H2S filter:
Instructions for use:
The following diagram shows how to modify the standard water trap and sample tubing to fit the H2S filter.
Note: When onsite the site engineer must have an unmodified water trap assembly in addition to the
modified water trap with a H2S filter in order to take readings with and without a filter.
1) Once the H2S filter is fitted follow the instructions as detailed on the front of the gas analyser
displayed when taking readings using a H2S filter.
Note: This is only for analysers fitted with the CO compensated cell.
Sample
Point
Sample
Tubing
Cut the
Sample
Tubing
Water
Trap
Insert
H
2
S
Filter
Gas Port
Connector
Standard Water Trap and Sample Tubing
Modified Water Trap and Sample Tubing with H
2
S Filter