DO700-en-GB_v2.3 3/15
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Zero Dissolved Oxygen Calibration
The meter receives a zero oxygen calibration before leaving the factory and only requires a zero
oxygen calibration when the electrode (or the electrode cap) is replaced or has been in use for a
relatively extended period of time (6 months or longer). To perform a zero oxygen calibration:
1.
Prepare 100mL of anaerobic water: In a 100 mL beaker add 5g anhydrous sodium sulfite
(Na2SO3) to 100 mL distilled water. Stir to dissolve. The anaerobic water will be usable in
24 hours.
2.
Polarize the DO electrode by connecting it into meter for 15 minutes and then perform a
standard calibration as described in the calibration section earlier in this manual.
3.
Place the electrode in the anaerobic water and press the CAL key to enter the calibration
mode. When the displayed value is
≤
0.15mg/L (
≤
5min) press the ENTER key.
4.
If the displayed value is
≤
0.02mg/L (within 5 minutes)
,
this indicates that the response time
and the residual current are normal and there is no need to perform the zero oxygen
calibration, press the ENTER key to the normal operating mode.
5.
If the displayed value is >0.15 mg/L after 5 minutes, this indicates that the response time of
the meter is too slow and there is too much residual current. In this case, replace the
membrane cap or remove the membrane cap and use the supplied polishing paper to lightly
wipe the gold plane’s cathode (the surface along the gold-polished arc) and clean the
surface of the cathode with a soft cloth or tissue. Clean the electrode with distilled water and
shake off the excess water. Add some electrolyte to the membrane cap, re-assemble, and
then perform a full scale and a zero oxygen calibration.
Salinity Calibration
Under normal circumstances, a salinity calibration is not required. The meter is equipped with an
automatic salinity compensation; In addition, a salinity calibration has been performed at the
factory prior to shipment; however a salinity calibration is required when the electrode is replaced
or has been in service for a relatively extended period of time. Refer to parameter P2 in previous
section for calibration procedure.
Barometric Pressure Setting
The meter is equipped with a manual barometric pressure adjustment. It is recommended that the
value be set according to the standard barometric pressure table when there is an excessive
change in barometric pressure while using meter. This ensures the accuracy of the barometric
pressure compensation. To change the barometric value refer to parameter P3 in the previous
section. Use the Table in Appendix C for barometric pressure values.
You, as the end user, are legally bound (EU Battery ordinance) to return all used
batteries, disposal in the household garbage is prohibited! You can hand over your
used batteries / accumulators at collection points in your community or wherever batteries
/ accumulators are sold!
Disposal: Follow the valid legal stipulations in respect of the disposal of the device at the
end of its lifecycle
