sewerin VARIOTEC 480 EX - Test Gases for the Adjustment

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5 Maintenance
5.2.2 Test gases for the adjustment
The following test gases can be used for adjustment:
Gas Suitable test gases for
Zero point Sensitivity
CH
4
● Fresh air ● Gas mixture
● 10 ppm CH
4
*)
● 100 ppm CH
4
*)
● 1000 ppm CH
4
*)
● 1.0 % vol. CH
4
*)
● 2.2 % vol. CH
4
*)
● 100 % vol. CH
4
C
3
H
8
● Fresh air ● 1 % vol. C
3
H
8
*)
● 100 % vol. C
3
H
8
C
4
H
10
● Fresh air ● 1 % vol. C
4
H
10
*)
CO ● Fresh air ● Gas mixture
● 40 ppm CO
O
2
● Gas mixture
(free from O
2
)
● 100 % vol. CH
4
● Fresh air
*)
in synthetic air
If more than one test gas can be used to adjust a gas, it does not
have to be adjusted with all test gases. However, adjusting with
more than one test gas increases the measurement quality.
Every gas must be adjusted separately, except for adjustment
with a gas mixture (see Section 5.2.3).
Replacement test gases are suitable for adjustment even though
they do not contain the gas to be tested, although the adjustment
error can be up to -15 % or +30 %.
Fresh air contains 20.9 % vol. O
2
and is therefore used with ox-
ygen to adjust the sensitivity.
Propane C
3
H
8
and butane C
4
H
10
can only be adjusted with indi-
vidual gas.