M&C TechGroup PMA 10S Operator's manual - Manual (Page 22)

22
Gas sampling and gas conditioning technology 9-1.1-ME
The correction factor is calculated as follows:
100
Correction factor =

(100 – O
2
-concentration)
It is incidental:
100

= 1,0526
(100 – 5)
For the gas mixture the rectified sum cross sensitivity then is calculated in good approximation :
1,0526 x -0,1123 Vol.% = -0,1182 Vol.%
The rectified sum cross sensitivity with change of sign now can be used for the correction of the
zero calibration. In this case zero had to be adjusted at +0,1182 Vol.%.
In case the cross sensitivities should be ignored in the above mentio ned example, this would re-
sult in a relative error of approximately 2%.
N O T E !
After zero calibration the span has to be calibrated too.
17.2 SPAN CALIBRATION
Before span calibration a finished zero calibration is necessary.
Connect a flexible PVC- or FEP-hose with the pressure reducer of the N
2
-zero-gas bottle. The
pressure reducer should have an output control range of max. 0 – 1,5 bar abs..
C A U T I O N !
The outlet pressure is only allowed to be adjusted at max. 0,1 bar. Oth-
erwise the measuring cell of the analyser will be destroyed.

Open the bottle valve and than the closed pressure reducer outlet valve and purge the
pressure reducer and the complete hose line for approximately 5 sec. the pressure reduc-
er and the complete hose line.

Check the adjusted control pressure and reduce if necessary to
≤ 0,1bar, then shut off the
pressure reducer valve again.

Connect the hose end of the instrument air or check gas bottle connection to the gas inlet
of the analyser.

Open the pressure reducer valve slowly, to avoid pressure peaks.

Adjust the flow rate to 50 Nl/hr at the flow meter.