VEGA VEGAPULS 56 Profibus PA - Manual (Page 32)

32 VEGAPULS 56 Profibus PA
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Mounting and installation
3.4 False echoes
The installation location of the radar sensor
must be selected such that no installations or
inflowing material cross the radar impulses.
The following examples and instructions
show the most frequent measuring problems
and how to avoid them.
Vessel protrusions
Vessel forms with flat protrusions can, due to
their strong false echoes, greatly affect the
measurement. Shields above these flat pro-
trusions scatter the false echoes and guaran-
tee a reliable measurement.
Intake pipes, i.e. for the mixing of materials -
with a flat surface directed towards the sen-
sor - should be covered with a sloping shield
that will scatter false echoes.
Vessel protrusions (slope)
Vessel protrusions (intake pipe)
Vessel installations
Vessel installations such as, for example
ladders, often cause false echoes. Make
sure when planning your measuring location
that the radar signals have free access to the
measured product.
Struts
Struts, like other vessel installations, can
cause strong false echoes that are superim-
posed on the useful echoes. Small shields
effectively hinder a direct false echo reflec-
tion. These false echoes are scattered and
diffused in the area and are then filtered out
as "echo noise“ by the measuring electronics.
Vessel installations
Struts
Correct Wrong
Correct Wrong
Ladder
Ladder
Shields
Correct Wrong
Correct Wrong
Shield
Shield