Calomat 7 - Siemens SIPROCESS GA700 Operating Instructions Manual

Commissioning
9.5 Zero point error
Accompanying gas (concentration 100 vol. %)
Water
Hydrogen
Since the zero point deviations are linear, it is easy to convert to lower interfering gas
concentrations.
In the case of interfering gases with a constant concentration, an interfering gas correction with
constant zero point offset can be carried out in the gas to be measured. If the concentration of
the accompanying gases changes during the oxygen measurement, a variable interfering gas
correction has to be carried out. An external concentration must be determined for each
interfering gas with a considerable zero point deviation. Its result is fed as interfering gas
concentration into the OXYMAT 7 analyzer module and the correction value is calculated
constantly.
Information on interference gas correction is available in the following operating manuals:
• Operating with the Local User Interface Table A-2 References 1 - Operating Manuals LUI
(Page 135)
• Operation with SIMATIC PDM Table A-3 References 2 - Operating Manuals PDM (Page 135)
9.5.2

CALOMAT 7

Overview
To determine the cross-interferences of accompanying gases with several interference gas
components, you must know the sample gas composition. The following table contains the zero
offsets for the carrier gas N
Table 9-6
96
as H equivalent values with 10% interference gas
2 2
Zero offset in the system H
Interference gas
CH
4
C H
2 6
C H
3 8
CO
CO
2
O
2
N O
2
NH
3
Ar
He
SF
6
SO
2
Synthetic air
H O (3%)
2
H O
2
H
2
in N
2 2
H equivalent values with 10% inference gas
2
Zero point deviation in
vol. % O absolute
2
-0.03
+0.26
1.77%
0.47%
-0.28%
-0.10%
-0.84%
0.19%
-0.83%
1.45%
-1.22%
6.32%
-2.15%
-1.47%
0.40%
0.38%
Rack-mounted device
Operating Instructions, A5E31874006-12