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AO2000
CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B
Air pressure value correction
When should the air pressure value be corrected?
The air pressure value must be checked and readjusted as required in the
following cases:
•
If the gas analyzer’s operating site altitude has changed since the last
calibration or
•
if the air pressure effect on the measured value is too high.
NOTE
An incorrect air pressure value will produce erroneous measurement values.
Limas11 IR, Limas21 UV, Limas21 HW and Uras26 with integral pressure sensor
and calibration cells
A pressure sensor is factory-installed in the Limas11 IR, Limas21 UV,
Limas21 HW and Uras26 analyzer modules. The pressure sensor is calibrated
to 1013 hPa. This is the reference pressure for the test gas concentration
when measuring the calibration cells.
If the air pressure value needs to be changed, the following steps are also
required
•
Calibrate the sample components with test gases and then
•
Measure the calibration cells.
Air pressure value correction
The current atmospheric pressure can be entered as a correction value for
each analyzer module or for all analyzer modules as a group.
Menu path
For one analyzer module:
MENU
→
Maintenance/Test
→
Analyzer spec. adjustm.
→
Atm. press. anlz
→
...
For all analyzer modules as a group:
MENU
→
Maintenance/Test
→
System
→
Atm. pressure
NOTE
If the pressure sensor is connected to the sample gas output line, the sam-
ple gas flow must be interrupted while calibrating the pressure sensor so
that the sample gas pressure does not distort the measured pressure.
