VEGA VEGAPULS 66 (≥ 2.0.0 - ≤ 3.8) Foundation Fieldbus - Manual (Page 19)

By using a standpipe, the influence of vessel installations and
turbulence can be excluded. Under these prerequisites, the meas-
urement of products with low dielectric values (from DK value 1.6) is
possible.
Note:
Measurement in a standpipe is not recommended for very adhesive
products.
Surge or bypass tubes must extend all the way down to the requested
min. level, as measurement is only possible within the tube.
Surge pipe
Make sure you provide the necessary upper vent hole in the surge
pipe. The hole must be aligned so that it and the polarisation marking
on the sensor flange are in the same plane (see illustration: "Pipe
antenna system in a tank").
max.
min.
2
1
Fig. 13: Pipe antenna system in a tank. The vent hole in the surge pipe must be
in one plane with the polarisation marking on the sensor.
1 Marking of the polarisation direction
2 Vent holde max. ø 5 mm (0.2 in)
If possible, the diameter of the sensor antenna should correspond to
the inner diameter of the tube. With VEGAPULS 66 this is approx.
50 mm (1.969 in) depending on the antenna. The sensor can be used
with tube diameters between 50 … 250 mm (1.969 … 9.843 in).
Bypass tube
As an alternative to the surge pipe in the vessel, a tube system outside
of the vessel is possible as a bypass tube. Select during setup the
function "Bypass tube".
Measurement in the
standpipe (surge or by-
pass tube)
VEGAPULS 66 • Foundation Fieldbus 19
4 Mounting
28453
-EN
-090305