VWR MD 8000 L, Руководство по эксплуатации

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Dissolved oxygen MD 8000 L
46
ba77218e01 11/2018
8.2.6 Zero point calibration
With a Zero point calibration , the zero point of the sensor is redetermined by
calibrating in a zero solution.
For most applications, an additional Zero point calibration is not required and
not recommended. Only with very rare applications can the accuracy of a cali-
bration be improved if a
Zero point calibration was carried out before.
The zero point calibration is best done prior to calibrating with a calibration
procedure (e.g. calibration in water vapor-saturated air or calibration via
comparison measurement)..
6. Using
<

> <

>
, set the correction factor to adjust the displayed mea-
sured value to the nominal value (value of the comparison measure-
ment). Then take over the adjustment with
<OK>
.
The meter switches to the measured value display.
The status display
[Factor] is active.
1. Connect the D.O. sensor to the meter.
2. Place the D.O. sensor in a solution that does not contain any dissolved
oxygen.
A solution not containing any dissolved oxygen can be prepared by
dissolving approx. 8 to 10 g sodium sulfite (Na
2
SO
3
) in 500 ml tap-
water. Carefully mix the solution. It may take up to 60 minutes until
the solution is free of oxygen.
3. In the menu for measurement and calibration settings (
<OK>
/ Calibra-
tion / Zero point calibration ), start the Zero point calibration .
The calibration point for the measured value 0 (DO Zero) is displayed.
O
2
7.92
mg/l
20.3°C
Compare
01.11.2018
08:00


DO Adjust