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1.
Operating principle
Electrode controls used for the automatic control of pumps
or electromagnetic valves as well as overflow or run-dry protection
in wells or tanks with conductive liquids. The liquid levels
are monitored by electrodes which give switching commands
to the electronic relay if they come into contact with the
liquid. For a two-point control system, you require two control
electrodes and one earth electrode will suffice. You can also
us a metallic, conductive tank wall as an earth connection
in place of the earth electrode.
However, we recommend the use of a separate earth electrode
in all cases.
2.
Recommendations for the design of the electrode
a)
Highly conductive liquids: if there is sufficent
space, we advice you to use several single electrodes
at a spacing of approx. 100 mm instead of a multiple electrode.
b) Poorly conductive liquids: if electrodes are
used in poorly conductive liquids, the electrode rods should
be mounted as close as possible to one another. For these
applications, we recommend the use of a multiple electrode
in place of several single electrodes.
3. Electrode
controls can or should not be used:
a) in non-conductive liquids /e.g. in mineral oils);
b) in liquids with a tendency to foam (e.g. possibly beer,
washing sodas etc.);
c) in liquids with a high level of steam generation and
condensate (e.g. at higher
temperatures);
d) in liquids with a tendency to form deposits (e.g. in
limonestone milk, oily waste etc.)
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