16
4 Mounting
OPTISOUND 3020 C • Two-wire 4 … 20 mA/HART
30507-EN-190318
Fig. 13: Inflowing liquid
Through the action of filling, stirring and other processes in the vessel,
dense foams which considerably damp the emitted signals may form
on the product surface.
If foams are causing measurement errors, the sensor should be used
in a standpipe or, alternatively, the more suitable guided radar sen-
sors (TDR) should be used.
Guided wave radar is unaffected by foam generation and is particu-
larly suitable for such applications.
If there are strong air currents in the vessel, e.g. due to strong winds
in outdoor installations or air turbulence, e.g. by cyclone extraction
you should mount OPTISOUND 3020 C in a standpipe or use a differ-
ent measuring principle, e.g. radar or guided radar (TDR).
By using a standpipe (surge or bypass tube), the influence of vessel
installations, foam generation and turbulence is excluded.
Standpipes must extend all the way down to the requested min. level,
as measurement is only possible within the tube.
Foam
Air turbulences
Standpipe measurement