Endress+Hauser Oxymax COS22 Series - Page 25

Oxymax COS22 Maintenance
Endress+Hauser 25
4. Carefully screw on the shaft sleeve as far as it will go.
After replacing, the sensor must be repolarized and recalibrated. Then insert the
sensor into the medium and check that no alarm is displayed on the transmitter.
10.4.3 Replacing membrane body
Removing the membrane body
1. Remove the sensor from the medium.
2. Clean the outside of the sensor.
3. Hold the sensor vertically and unscrew the shaft sleeve.
 The membrane body is either in the shaft sleeve or is still on the glass portion
with the anode and cathode.
4. Remove the membrane body. For this purpose, use the tool provided to push out the
membrane body.
5. Dispose of the old membrane body and the old electrolyte.
6. Take a new membrane body out of its packaging.
Top up the electrolyte and install the membrane body
1. Fill fresh electrolyte from the supply bottle into the membrane body.
2. Remove all air bubbles from the electrolyte by tapping the side of the membrane body
(using a pen or pencil, for example).
3. Hold the sensor vertically and carefully push the membrane body, filled with
electrolyte, on the glass portion.
4. Carefully screw on the shaft sleeve as far as it will go.
After replacing, the sensor must be repolarized and recalibrated. Then insert the
sensor into the medium and check that no alarm is displayed on the transmitter.
10.4.4 Replacing glass body with cathode
NOTICE
Polishing the cathode can cause impaired function or total failure of the sensor.
‣
Do not clean the cathode mechanically.
If the cathode is coated, replace the glass body:
1. Hold the sensor vertically and unscrew the shaft sleeve: item 6 .
2. If the membrane body (item 5) remains on the glass body (item 7) and not in the
shaft sleeve, remove it from the glass body.
3. Flush the glass body, along with the anode and cathode, using distilled water.
4. Pull the used glass body out of the holder.
5. Dry the inside of the electrode holder.
6. Plug a new glass body (from the membrane kit) into the holder so that it fits. Ensure
that you do not damage the electrical contact pins.
7. Fill the membrane body with electrolyte then screw the shaft sleeve back on.