128
EL3000
CONTINUOUS GAS ANALYZERS | OI/EL3000-EN REV. D
… 9 Calibration
Limas23 – Instructions for calibration
Calibration methods
• Automatic calibration:
zero point/end-point calibration
• Manual calibration:
zero point/end-point calibration
Calibration Cells
The use of calibration cells (option) allows the end-point
calibration of the Limas23 without the need to use test gas
containers.
There is a calibration cell available for each measured
component. It is filled with a test gas; its concentration is
matched with the measuring range of the measured component.
The calibration cells are located on the calibration wheel, which
is installed before the sample detector. The calibration cells are
retracted into the emission path during the end-point
calibration.
Information about the installed calibration cells is included in the
device data sheet.
The concentration set points of the test gases in the calibration
cells should be checked at large time intervals (see
Limas23 – measuring the calibration cell
(recommended: once a year).
Manual Calibration
In the ‘Manual calibration’ menu, you choose whether during the
end-point calibration of Limas23 all measured components are
calibrated together (typical case) or if each measured
component is calibrated individually (special case).
You also need to select whether the end-point calibration of the
Limas23 is done with calibration cells or with test gases.
Calibration of the Limas23 together with Magnos206 or
Magnos28 or oxygen sensor
Automatic calibration
When performing a zero point calibration of the Limas23, a
single-point calibration of the Magnos206 (see
on page 130) or the Magnos28 (see
on page 131) or the oxygen sensors (see
on page 140) (if configured) runs at the same time.
The test gas must be selected accordingly.
Manual Calibration
For the Limas23 sample components, the zero point/end-point
calibration is fixed as the calibration method.
The calibration method for the measurement component of the
Magnos206 or Magnos28 needs to be configured.
When single-point calibration is configured, it is possible to
choose during manual calibration whether this sample
component should be calibrated individually or together with the
Limas23 sample components.
Limas23 calibration with internal cross-sensitivity
correction
During the calculation of the calibration, possible electronic
cross-sensitivity corrections are switched off by other sample
components measured with the Limas23.
The following information should therefore be noted in
particular: The following information should therefore be noted
in particular:
Zero-point
calibration
All
the available sample components must also always be
calibrated during end-point calibration.
When performing the calibration, all measured components are
normally calibrated together (‘All’ menu selection).
In special cases, each sample component must be calibrated
individually in the following order:
1. the sample component which is not corrected
2. the sample component which is affected by the smallest
number of corrections,
3. the sample component which is affected by the largest
number of corrections.
Example:
Sample components
NO, SO
2
, NO
2
Cross-sensitivity correction Cross-
sensitivity correction
NO by SO
2
and NO
2
,
SO
2
by NO
2
,
NO
2
is not corrected
Resulting sequence for zero-point
calibration
1. NO
2
2. SO
2
3. NO
End-
point calibration
All
the available sample components must also always be
calibrated during the end-point calibration.
Here, a corrected sample component may only be calibrated
using a test gas contain no components which cause cross-
sensitivity, i.e. which only consists of the sample component and
an inert gas, such as N
2
.
