OMGEMN1.41
GEM2000 Range Gas Analysers
Page 72
Copyright 2009 Geotechnical Instruments (UK) Limited
8.7 Confirm Calibration
This feature allows the operator to store the accuracy of the instrument in the event log.
8.7.1 Confirm Multi-Gas
The ‘Span Multi-gas’ option must only be used when the calibration gas being used is a
combination of CH
4
, CO
2
and O
2
i.e. Mixture 1.
It is probably easiest at this point to set the span values of the different gases that will
be used to confirm the calibration of the instrument. The span value is the concentration
of the calibration gas.
Step 1
Press
to edit target concentrations.
Step 2
From the ‘Check Calibration’ screen:
Scroll using
and press
to select required gas channel.
Enter the appropriate value for the highlighted channel then press
.
When using gas mixture 1 set CH
4
at 5%, CO
2
at 5% and O
2
at 6%.
Press
Step 3
Attach the flow regulator with mixture 1.
Do not run the pump.
Step 4
Attach the regulator to the inlet port and turn the gas on.
Step 5
Allow the gas to flow through the unit for approximately two minutes or
until reading stabilises.
Step 6
From the ‘Check Calibration’ screen:
Press
to enter the ‘Calibration Menu’.
Scroll
to ‘Confirm Calibration’.
Press
to select ‘Confirm Calibration’.
Press
to select ‘Confirm Multi Gas’.
Press
Finished
.
This information will then be stored in the event log and can be
downloaded and viewed using GAM.
8.7.2 Confirm Channels Independently
This option can be used if the gas being used is not a combination of CH
4
, CO
2
and O
2
i.e.
Mixture 1 or if the confirmation of a single channel is required.
It is probably easiest at this point to set the span values of the different gases that will
be used to confirm the calibration of the instrument. The span value is the concentration
of the calibration gas.
Step 1
Press
to edit target concentrations.
