VEGA VEGAPULS 56 Profibus PA - Manual (Page 34)

34 VEGAPULS 56 Profibus PA
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Direct sensor perpendicularly to the product surface
Correct Wrong
Ladder
Ladder
Mounting and installation
Horn antenna: correct and wrong socket length
Correct Wrong
Wrong
Mounting on a vessel with parabolic tank top
Correct
~ 1 /
2
vessel
radius
Wrong
>10 mm
3.5 Installation mistakes
Socket piece too long
If the antenna is mounted in a socket exten-
sion that is too long, false reflections are
caused, and measurement is hindered. Make
sure that the horn antenna protrudes at least
10 mm out of the socket piece.
Wrong orientation to the product
A sensor orientation which does not point
directly to the product surface causes weak
measuring signals. Direct the sensor axis
perpendicularly to the product surface to
achieve optimum measuring results.
Parabolic effects on dished or arched
vessel tops
Round or parabolic tank tops act like a para-
bolic mirror on the radar signals. If the radar
sensor is placed at the focal point of such a
parabolic tank top, the sensor receives am-
plified false echoes. The optimum mounting
position is generally in the range of half the
vessel radius from the centre.
10 mm