6 Maintenance
OxyMax W COS 41
20
Hauser
6.2.2 Replacing the sealing ring
Replacing the sealing ring (see Fig. 3.14 on page 12, Pos. 2) is only necessary when it
is visibly damaged. For replacement, use only the supplied sealing rings COY 31-OR.
6.2.3 Replacing the electrolyte
The electrolyte COY 3-F is slowly used up during measuring operations. The cause of
this is electrochemical substance reactions. No substance reactions occur in de-ener-
gised state and the electrolyte is not used up.
The theoretical life of an electrolyte filling for use in air-saturated drinking water at 20°C
is max. 5 years. The electrolyte life is shortened by diffused, dissolved gases such as
H
2
S, NH
3
or high concentrations of CO
2
.
Particular loads occur with:
•
anaerobic stages (e.g. denitrification)
•
Strongly polluted industrial wastewater, particularly at high temperatures
To replace the electrolyte, proceed as follows:
1. Remove the membrane cap (see Chap. 6.2.4).
2. Replace the electrolyte and, if necessary, the membrane cap.
3. Place the membrane cap back on the membrane body and screw the cap to the
stop.
#
Warning!
Risk of acid burns!
The electrolyte is strongly alkaline. You must follow the appropriate occupational safety
regulations. Always wear protective gloves and goggles with handling electrolytes.
6.2.4 Replacing the membrane cap
Remove the old membrane cap
1. Remove the sensor from the medium.
2. Unscrew the protection basket.
3. Clean the outside of the sensor (see page 18).
4. Unscrew the membrane cap.
5. If necessary, clean the gold cathode (page 19) or replace the sealing ring if it is dam-
aged (page 20).
6. Rinse the electrode holder with drinking water.
Install the new membrane cap
"
Caution!
Only use the membrane cap COY 31-WP for the COS 41 sensor
(colour: black).
7. Make sure that there are no dirt particles on the sealing surface.
Summary of Contents for OxyMax W COS 31
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