Oxymax H COS21D
Maintenance
Hauser
25
7.1.2
Cleaning the cathode
"
Caution!
COS21D-B:
Do not clean the cathode mechanically! Polishing the cathode may cause functional errors or
total failure of the sensor.
COS21D-A und COS21D-C:
Clean coated cathodes with a polishing sheet (included in membrane kits).
1.
Water the polishing sheet.
2.
Take the polishing sheet into your palm.
3.
Polish the cathode in an eccentric movement for several seconds.
7.2
Replacing wear and tear materials
Parts of the sensor will suffer wear and tear during operation.
Suitable action can restore normal operating functionality. This action includes:
#
Warning!
Before beginning replacing, switch off the power supply at the transmitter.
7.2.1
Replacing the sealing ring
Replacing the sealing ring is only necessary when it is visibly damaged. For replacement, use only
original sealing rings.
7.2.2
Replacing the electrolyte
The electrolyte is slowly used up during measuring. The cause of this is electrochemical
substance reactions. No substance reactions occur in the de-energized state and the electrolyte
is not used up.
The electrolyte life is shortened by diffused, dissolved gases such as H
2
S, NH
3
or high
concentrations of CO
2
.
The theoretical service life of an electrolyte filling for use in air-saturated drinking water at 20
°C (68 °F) is as follows:
• COS21D-A: 100 weeks
• COS21D-B/C: 20 weeks
Action
Cause
Replacing the sealing ring
visual damage to the sealing ring
Replacing the electrolyte
unstable or implausible measuring signal or electrolyte soiling
Replacing the membrane cap
uncleanable membrane, damaged membrane (hole or overstretch)
