Span calibration – M&C TechGroup PMA 50 EEX Operator's manual User Manual
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Gas sampling and gas conditioning technology
9-3.15-ME
Shut the output valve of the pressure regulator and bottle valve and separate the tube conne c-
tion to the analyser.
N O T E !
After zero calibration the span has to be calibrated too.
18.2
SPAN CALIBRATION
N O T E !
In case the oxygen concentration of the sample gas is below 30% O
2
, the
calibration can be effected with dry air. Should the concentrations be
higher, ideally, the test gas should correspond to the span value !
Before calibrating the span 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.
W A R N I N G !
The pressure reducer should have a maximum outlet measuring
range of 0-1,5 bar abs. and should always be adjusted to a low
outlet pressure of max. 0,1 bar. 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;
Flush the pressure regulator and the tubing for about 5 seconds;
Check adjusted control pressure and reduce to ≤ 0,1bar if necessary then shut the outlet valve
of the pressure regulator again.
Connect the free tube end of the test gas bottle connection with the gas inlet of the analyser
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 by means of the needle valve of the flow meter.
The volume flow of the calibration gas should always correspond to the sample gas volume
flow;
N O T E !
Always calibrate at the gas flow used for the measurement too.