Endress+Hauser OxyMax W COS 31, Operating Instructions Manual

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6 Maintenance OxyMax W COS 41
18 Hauser
6 Maintenance
Maintenance work must carried out at regular intervals. To ensure that it is carried out,
we recommend you enter the maintenance dates into an operations logbook or in an
operations calendar in advance.
The following activities must be carried out:
•
Cleaning the sensor
In particular when the membrane is soiled (see Chapter 6.1).
•
Check the measuring function
A simple inspection of the measuring function is to remove the sensor from the
medium. Clean and dry the membrane. After about 10 minutes, measure the oxygen
saturation index in air (without recalibration). The measured value should be near to
102% SAT (display of O
2
saturation with COM 2x3 by pressing 4 times »+« - key).
•
Replace a defective membrane or one which cannot be cleaned any more.
•
Recalibration (see Chapter 5.3.1)
!
Note!
For regular automatic sensor cleaning, we recommend equipping
the measuring point with a fully-automatic cleaning system,
e. g. Chemoclean (see "Accessories" on page 22).
6.1 Cleaning the outside of the sensor
The measurement can be corrupted by sensor fouling or malfunction, e.g.:
•
Coatings on the sensor membrane
→
cause longer response times and a reduced slope.
•
Soiling or poisoning of the electrolyte
→
causes longer response times and false measurement.
To ensure reliable measurement, the sensor must be cleaned at regular intervals. The
frequency and intensity of the cleaning operation depend on the measuring medium.
Clean the sensor:
•
before every calibration
•
at regular intervals during operation as necessary.
•
before returning it to Hauser for repairs.
Depending on the type of soiling, proceed as follows:
"
Caution!
After cleaning, rinse the sensor with copious amounts of clean water.
Type of soiling Cleaning measure
Salt deposits Immerse the sensor in drinking water or in 1-5% hydrochloric acid
for a few minutes. Afterwards, rinse it with copious amounts of water.
Dirt particles on the sensor body
(not the membrane)
Clean the sensor body mechanically with water and a suitable brush.
Dirt particles on the membrane cap or
the membrane Clean the membrane with water and a soft sponge.