8
Maintenance and Repair Work on the Sensor
User qualification: instructed user, see
Chapter 1.2 ‘User qualification’ on page 49
Maintenance interval:
Maintain the sensor regularly in order to avoid
over-metering in the event of a sensor failure.
Please note the applicable national guidelines
for maintenance intervals.
Cooling water: weekly to monthly, depending
on water quality.
CAUTION!
–
Do not touch the electrodes or
bring them into contact with sub‐
stances containing grease.
–
Never try to clean the diaphragm
with alkaline solutions, cleaning
reagents or using mechanical
means (brush or similar).
Maintenance work:
1.
Check the diaphragm cap for deposits
or air bubbles.
ð
Remove deposits when necessary,
2.
Use a suitable measuring instrument
(e.g. DPD) to check the display value of
the sensor on the measuring/control
unit.
ð
Re-calibrate the sensor if neces‐
sary.
Cleaning the diaphragm:
Try to clean the diaphragm carefully if the dia‐
phragm is dirty and the sensor cannot be cali‐
brated. First dismantle the sensor. Gently
remove any adhering dirt:
Rinse the diaphragm under a gentle
stream of cold water.
ð
Now fill the sensor with electrolyte,
allow it to run in and recalibrate.
Replacing the diaphragm:
Replace the diaphragm cap if calibration is no
longer possible even after the diaphragm has
been cleaned or if the diaphragm is damaged.
To do so, refer to the Calibration
chapter.
Repair of the sensor:
The sensor can only be repaired in the manu‐
facturer's factory. To do so, return to the manu‐
facturer in its original packaging.
Maintenance and Repair Work on the Sensor
67
