VEGA VEGAPULS 45 Profibus PA - Manual (Page 17)

VEGAPULS 42, 44 and 45 – Profibus PA 17
24908-EN-041227
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.
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
min. 300 mm
Vessel center or
symmetric axis
Mounting and installation
When mounting on dished vessel tops, make
sure the antenna is at least as long as the
extended socket tube.
3.2 Measurement of liquids
Flange antennas
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.
With longer DIN socket pieces, make sure
that the horn antenna still protrudes slightly
out of the socket.
Mounting on DIN socket piece
Mounting on a dished vessel top; max. socket length
dependent on the flange size and possibly on the
antenna extension (see „8.4 Dimensions“).
Reference plane
< 135 mm (DN 50)
< 210 mm (DN 80)
< 310 mm (DN 100, DN 150)
Vessel center or
symmetric axis
<135…310mm
(250…425mm
with antenna
extension)