VEGA VEGAPULS 81 - Manual (Page 44)

44 VEGAPULS 64 and 81
Mounting and installation
4.5 False echoes
The installation place of the radar sensor
should be selected so, that no struts or mate-
rial inflow cross the radar signals. The follow-
ing examples and instructions show the most
frequent measuring problems and how they
can be avoided.
Vessels with shoulders
Vessel forms with flat shoulders to the antenna
can considerably influence the measurement
due to their hard false echoes. Screens above
these flat shoulders spread the false echoes
and ensure a reliable measurement.
Inlet gates, e.g for material mixing with flat
upper side pointing to the radar sensor should
be covered by an angle screen. Hence the
false echo is gated out.
Vessels with shoulders (flat shoulders)
Vessel with shoulders (inlet gate)
Vessel installations
Vessel installations such as e.g. a ladder often
cause false echoes. Provide free access of the
radar signals to the measured product when
planning your measuring point.
Struts
Struts as well as vessel installations can cause
strong fale echoes and superimpose the useful
echo. Small screens avoid effectively a direct
false echo reflection. The false echoes are
diffusely gated out and filtered out by the
measuring electronics as “echo noise“.
Vessel installations
Struts
Correct Wrong
Correct Wrong
Correct Wrong
Correct Wrong
Ladder
Ladder
Screens