ABB AO2040 - Magnos28: Substitute Gas Calibration

258 AO2000 CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B
Magnos28: Substitute gas calibration
Example
Substitute gas calibration of the Magnos28 analyzer module is described
using the example of "Purity measurement of CO
2
".
Purity measurement of CO
2
For CO
2
purity measurements, the smallest concentrations of O
2
are meas-
ured in CO
2
, e.g. 0 to 1 vol.% of O
2
in CO
2
.
Calibration with substitute gas
Since O
2
in CO
2
is not available as a test gas and due to the O
2
zero shift
caused by CO
2
, the analyzer module is factory-set for calibration with sub-
stitute gas.
In this case a measurement range for 0 to 25 vol.% of O
2
in N
2
is calibrated in
addition (N
2
and O
2
/N
2
mixtures are available practically everywhere).
Measuring ranges
Component 1 O
2
in CO
2
Meas. range 1 0 to 1 vol.%
Meas. range 2 0 to 15 vol.%
Meas. range 3 0 to 25 vol.%
Meas. range 4 0 to 100 vol.%
Component 2 O
2
in N
2
(substitute gas) Meas. range 1 0 to 25 vol.%
Calibration parameters
Calibration method Substitute gas calibration
Zero component Component 1 Meas. range 1 or
Component 2 Meas. range 1
Span component Component 2 Meas. range 1
Calibration
• Calibrate zero with CO
2
(component 1) or N
2
(component 2).
• Calibrate span with dried air (contains 20.96 vol.% of O
2
).
Other measurement tasks
For other measurement tasks select the test gases and measurement ranges
in a similar manner according to the sample gas composition.