M&C TechGroup PMA 50 EEX Operator's manual - Manual (Page 23)

23
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.