VEGA VEGAPULS 51K…54K 4 … 20 mA; HART compact sensor - Manual (Page 23)

VEGAPULS 51K … 54K 23
21750-EN-031222
Incorrect
Incorrect
- 100 mm
(250 mm)
< 100 mm
(250 mm)
Mounting and installation
3.5 Common installation mistakes
Socket piece too long
If the sensor is mounted in a socket exten-
sion that is too long, strong false echoes are
generated which interfere with the measure-
ment. Make sure that the horn antenna pro-
trudes out of the socket piece.
Flange antenna: Correct and unfavourable socket
length
Flange antenna: Correct and unfavourable socket
length
Unfavour-
able
Correct Unfavourable
Mounting on a vessel with parabolic tank top
Correct
~ ½
vessel
radius
Correct
Parabolic effects on dished or rounded
vessel tops
Round or parabolic tank tops act on the radar
signals like a parabolic mirror. 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
location is generally in the range of half the
vessel radius from the centre.
≥
10 mm
Reference plane
Wrong orientation to the product
Weak measuring signals are generated if the
sensor is not directly pointed at the product
surface. Orient the sensor axis perpendicu-
larly to the product surface to achieve opti-
mum measuring results.