7
UK
3.2 Restriction of the application area
• Not suitable for abrasive media (e�g� quartz sand) and heavy bulk material�
• Not suitable for ozonised water�
• For use in aggressive media (acids and alkali):
►
Check the compatibility of the product materials beforehand
(
→ Technical data sheet).
• Media which are very inhomogeneous, separate from each other thus forming
separation layers (e�g� oil layer on water):
►
Check the function by an application test�
• Air or gas bubbles may lead to unwanted switching operations�
►
Check the function by an application test� If required, adapt the sensitivity or
�
• Do not expose the probe tip to intensive sun radiation (UV radiation)�
4 Function
4.1 Measuring principle
The unit operates on the impedance spectroscopy
method� It evaluates the electrical behaviour of the
media to be monitored in the frequency range between
50 and 200 MHz� An electrical field is generated by
the probe tip which is influenced by the level� The
nature of the medium and deposits or foam have
different electrical characteristics that are used for the
evaluation�
Fig. 5-1
