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5 Maintenance
5.2.5.1 Adjusting the zero point
For all gases except oxygen O
2
, the zero point is adjusted follow-
ing the same procedure.
Note:
When adjusting the zero point of carbon dioxide CO
2
, a carbon
dioxide filter must be used.
This applies to both the zero point adjustment for
Adjustment
CO2
in the menu and
Adjustment gas mixture warning
.
1. Make sure that only fresh air is being drawn in.
2. Open
Settings
.
3. Select
Adjustment
menu item.
4. Select the desired adjustment (for example,
Adjustment CH4,
Adjustment gas mixture warning
).
5. Wait at least 1 minute. The displayed reading must be stable.
Note:
For
Adjustment gas mixture warning
and
Adjustment gas
mixture gas measuring
,
all
values must be stable. The time
required for this can vary depending on the specific gas.
6. From the menu select the method you wish to use to adjust
the zero point.
−
e.g. for
Adjustment CH4
:
Zero point
−
e.g. for
Adjustment gas mixture warning
:
Fresh air
7. Press
OK
to confirm.
This adjusts the zero point. The reading shows zero (0.00 %
vol. / 0 ppm). (Except for
Adjustment gas mixture…
: menu
item: the value for oxygen O
2
is 20.9 % vol.)
5.2.5.2 Adjusting the sensitivity
For all gases except oxygen O
2
, the sensitivity is adjusted follow-
ing the same procedure.
