42/24-10 EN Rev. 9
Chapter 8: Gas Analyzer Calibration
8-C-5
Limas11: Notes for Calibrating
Calibration
Calibration can be performed in range 1 and range 2 for each sample component.
It is always a common calibration and thus affects both ranges.
For additional information on measurement ranges, please refer to “Limas11,
Uras26: Notes for Changing Measurement Range Limits” section, page 7-A-3.
Calibration Cells
The use of calibration cells allows the Limas11 analyzer module to be calibrated
without using test gas containers.
A maximum of 5 calibration cells can be installed. Each calibration cell is filled
with a test gas matched to the sample components and measurement ranges set
up in the corresponding beam path.
Test Gases for Zero
Calibration
A zero gas is required for each zero calibration.
In addition to nitrogen, ambient air can be used for zero calibration. Water vapor
must be absorbed using a cooler. If the ambient air contains sample gas compo-
nents, these must be removed with a suitable absorber.
Test Gases for Span
Calibration without
Calibration Cells
A test gas is required for each measurement component for span calibration
without calibration cells. The span gas concentration should be 70-80% of the
end value of the largest measurement range.
Test Gases for Span
Calibration of
Suppressed Ranges
For suppressed ranges, the span gas concentration must be within the suppressed
range. If possible, it should be equal to the end value of the suppressed range (and
thus the end value of the larger measurement range).
Test Gas for
Automatic Calibration
In principle a test gas for each sample component is required for the internally or
externally controlled automatic calibration.
A test gas mixture containing each sample component in the appropriate con-
centration may be used only when all sample components have no mutual cross-
sensitivity and / or carrier gas influences.
Continued on next page
