M&C TechGroup PMA 50 EEX Operator's manual - Manual (Page 28)

28
Gas sampling and gas conditioning technology 9-3.15-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 for
0 Vol.% oxygen:
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 +0,12 Vol.%.
In case the cross sensitivities should be ignored in the above mentioned example, this would r e-
sult in a relative error of approximately 2%.
N O T E !
After zero calibration the span has to be calibrated too.
If the span is not calibrated with 100 Vol.% oxygen here eventually it is also a correction of the
cross sensitivities necessary.
Example: span calibration with air
The correction factor is calculated as follows:
(100
– O
2
-concentration)
Correction factor =

100
It is incidental:
100
– 20,93

= 0,7907
100