VEGA VEGAPULS 54K enamel - Manual (Page 11)

VEGAPULS 54K enamel 11
24 101-EN-041227
2.3 False echoes
The radar sensor must be installed at a loca-
tion where no installations or inflowing material
cross the radar pulses. The following exam-
ples and instructions show the most frequent
measuring problems and how to avoid them.
Vessel protrusions
Vessel forms with flat protrusions can make
measurement very difficult due to their strong
false echoes. Baffles mounted above these
flat protrusions scatter the false echoes and
guarantee 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 an angled baffle
that scatters false echoes.
Vessel protrusions (ledge)
Vessel protrusions (intake pipe)
Correct Incorrect
Correct Incorrect
Mounting and installation
On dished vessel tops, please do not mount
the instrument in the centre or close to the
vessel wall, but approx.½ vessel radius from
the centre or from the vessel wall.
Dished tank tops can act as paraboloidal
reflectors. If the radar sensor is placed in the
focal point of the parabolic tank top, the radar
sensor receives amplified false echoes. The
radar sensor should be mounted outside the
focal point. Parabolically amplified echoes are
thereby avoided.
Mounting directly on flat vessel top
Reference plane
Mounting on round vessel tops
Reference plane
1 /
2
vessel
radius
Horn antenna directly on the vessel top
If the stability of the vessel will allow it (sensor
weight), flat mounting directly on the vessel
top is a good and cost-effective solution. The
top side of the vessel is the reference plane.