13
4 Mounting
VEGAPULS 31 • Two-wire 4 … 20 mA/HART
57820-EN-191014
4.2 Mounting instructions
Radar sensors for level measurement emit electromagnetic waves.
The polarization is the direction of the electrical component of these
waves.
The polarization direction is marked on the housing, see following
drawing:
1
Fig. 5: Position of the polarisation
1 Marking of the polarisation
Note:
When the housing is rotated, the direction of polarization changes
and hence the influence of the false echo on the measured value.
Please keep this in mind when mounting or making changes later.
The lower side of the radar antenna is the beginning of the measur-
ing range. It is at the same time the reference plane for the min./max.
adjustment, see following diagram:
1
Fig. 6: Reference plane
1 Reference plane
When mounting the sensor, keep a distance of at least 200 mm
(7.874 in) from the vessel wall. If the sensor is installed in the center
of dished or round vessel tops, multiple echoes can arise. However,
these can be suppressed by an appropriate adjustment (see chapter
"
Set up
").
If you cannot maintain this distance, you should carry out a false
signal suppression during setup. This applies particularly if buildup on
the vessel wall is expected. In such cases, we recommend repeating
the false signal suppression at a later date with existing buildup.
Polarisation
Reference plane
Installation position
