beautypg.com

M&C TechGroup PMA 50 EEX Operator's manual User Manual

Page 28

background image

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