VEGA VEGAPULS 81 - Manual (Page 46)

46 VEGAPULS 64 and 81
4.6 Installation fault
Socket piece too long
When mounting the antenna in a too long
socket piece, strong false reflections are
caused, aggravating a measurement. Note
that the horn antenna protrudes at least 10 mm
out of the socket piece. When using a rod
antenna, the socket piece must have a length
of max. 150 mm (with a rod length of 485 mm
the length of the socket piece must be max.
250 mm).
Mounting and installation
In some cases the lower flange antenna is
used. Even here it is important that the socket
piece is as short as possible (< 15 mm).
Horn antenna: Correcto and wrong length of
the socket piece
Rod antenna: Correct and wrong length of the
socket piece
Paraboilic effect on dished boiler head
or basket arch vessel
Round or paraboilic tank cover act for the
radar signal like a paraboilic mirror. If the radar
sensor is placed to the focus of such a
paraboilic tank cover the sensor receives
amplified false echoes. The optimum mounting
is generally in the range of the half vessel
radium from the centre.
Lower flange antenna: Length of the socket
piece as short as possible
Correct mounting on the vessel with parabolic
tank top
Correct Wrong
>10mm
10mm
< 150 mm
Correct
Correct Wrong
Correct Wrong
~ 1 /
2
Vessel
radius