VEGA VEGAPULS 54K enamel - Manual (Page 10)

10 VEGAPULS 54K enamel
24 101-EN-041227
2.2 Measurement of liquids
Horn antenna on DIN socket piece
Radar sensors are usually mounted on short
DIN socket pieces. The lower side of the
instrument flange is the reference plane for
the measuring range. The antenna must
always protrude out of the flange pipe.
Mounting on DIN socket piece
Mounting on longer DIN socket pieces
Mounting on round vessel tops
Reference plane
> 10 mm
> 10 mm
If the DIN socket piece is longer, please
make sure that the horn antenna protrudes at
least 10 mm out of the socket.
When mounting on dished or rounded vessel
tops, the antenna must also protrude at least
10 mm (longer side of socket).
Mounting and installation
Emission cone and false echoes
The radar signals are focused by the an-
tenna system. The signals leave the antenna
in a conical path similar to the beam pattern
of a spotlight. This emission cone depends
on the antenna used.
Any object in this beam cone will reflect the
radar signals. Within the first few meters of
the beam cone, tubes, struts or other installa-
tions can interfere with the measurement. At a
distance of 6 m, the false echo of a strut has
an amplitude nine times greater than at a
distance of 18 m.
At greater distances, the energy of the radar
signal distributes itself over a larger area,
thus causing weaker echoes from obstruct-
ing surfaces. The interfering signals are
therefore less critical than those at close
range.
If possible, orient the sensor axis perpen-
dicularly to the product surface and avoid
vessel installations (e.g. pipes and struts)
within the 100% emission cone.
If possible, provide a "clear view“ to the
product inside the emission cone and avoid
vessel installations in the first third of the
emission cone.
Optimum measuring conditions exist when
the emission cone reaches the measured
product perpendicularly and when the emis-
sion cone is free from obstructions.