M&C 1803436, Instruction Manual

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Note
After zero calibration, the full scale value must also be calibrated!
18.2
FULL SCALE VALUE CALIBRATION
Note
For oxygen concentrations of the sample gas below 30 % O
2
, dry air can be used for
calibration. Higher concentrations ideally require a test gas corresponding to the full
scale value!
Before calibrating the full scale value, always check the zero point.
The following calibration procedure has to be carried out:

Adjust measuring range selection switch to the range in which the calibration will be carried out.

Connect the flexible PVC or Viton tube with the bottle pressure reducer of the test gas bottle, if necessary
with ambient air or instrument air.
Warning
The pressure reducer should have a maximum outlet measuring range of 0 to
1.5 bar abs. and should always be adjusted to a low outlet pressure of max.
1.1 bar abs. This protects the measuring cell against destruction due to high
pressure!

First open the bottle valve, then open the closed output valve of the pressure regulator;

Purge the pressure regulator and the tubing for about 5 seconds;

Check adjusted control pressure and reduce to ≤ 1.1 bar abs. if necessary, then shut-off the outlet valve of
the pressure regulator again.

Connect the free tube end of the test gas bottle connection to the gas inlet of the analyzer or, if available,
the external calibration valve;

Open slowly the output valve of the pressure reducer in order to avoid pressure peaks;

Set the test gas volume flow to max. 60 l/h using the needle valve of the flow meter. The volume flow of
the calibration gas should always correspond to the sample gas volume flow;
Note
Always calibrate at the same gas flow as used for the measurement.

Wait approx. 30 seconds until the display is stable. If necessary, adjust the O
2
-value of the test gas via the
end value potentiometer 9 (Figure 1) (with a screw driver at air 20.93 %);