G200 Analyser Range
OMG200N1.23
©
Copyright 2010 Geotechnical Instruments (UK) Limited
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43
8.4 User Calibration Trouble Shooting
Error Remedy
User Zero failed
A possible reason for this is that the instrument is trying to zero
to a level which is outside the predetermined range set when the
unit was calibrated at the factory. To rectify this, first ensure the
unit contains absolutely none of the gas which is being zeroed by
flushing thoroughly with nitrogen. If it will not zero, then refer to
the instructions given in the ‘Factory Settings’ section. If the
instrument continues to fail to zero then the unit must be
returned to the manufacturer for investigation.
Calibration failed
Check the span target is set to the correct value, if not, correct
and retry spanning the channel. Repeat the entire procedure,
including zeroing the channel and then calibrate the span. Ensure
the reading is stable before spanning the channel.
User Calibration Explained:
User calibration is a means of optimising the performance of the instrument to the current
operating conditions such as ambient temperature and pressure as well as correcting for
instrument drift caused by lamp and filter settling.
In general, the instrument should not require calibration more than once a month, but we do
recommend verifying the instrument’s operation each day.
User calibration has two operations and each may be performed individually, however for a
complete user calibration both must be completed.
Factory Calibration (Curve 1)
The G200 instruments are ‘Factory’ calibrated and stable.
User Calibration
0.4
0.5
0.6
0.7
0.8
0.9
1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Curve 1 - Factory
Curve 2 - Zero
Curve 3 - Span
B
C
D
A
