VEGA VEGAPULS 66 (≥ 2.0.0 - ≥ 4.0.0) 4 … 20 mA_HART - four-wire - Manual (Page 22)

22
4 Mounting
VEGAPULS 66 • 4 … 20 mA/HART - four-wire
36520-EN-121011
•
For the parameter adjustment, select "Application standpipe" and
enter the tube diameter to compensate errors due to running time
shift
•
A false signal suppression with integrated sensor is recommended
but not mandatory
•
The measurement through a ball valve with complete run is pos-
sible
Constructional requirements on the bypass pipe:
•
Material metal, smoother inner tube
•
In case of an extremely rough tube inner surface, use an inserted
tube (tube in tube) or a radar sensor with tube antenna
•
Flanges are welded to the tube according to the orientation of the
polarisation level
•
Gap size with junctions ≤ 0.1 mm, for example, when using a ball
valve or intermediate flanges with single pipe sections
•
The antenna diameter of the sensor should correspond to the
inner diameter of the tube
•
Diameter should be constant over the complete length
Instruments for a temperature range up to 250 °C or up to 450 °C
have a distance piece between process fitting and electronics hous-
ing. Ths distance piece is used for thermal decoupling of the electron-
ics against high process temperatures.
Information:
The distance piece must only be incorporaed up to max. 50 mm in
the vessel installation. Only then, a reliable temperature decoupling is
guaranteed.
max. 50 mm (1.97"
)
1
2
3
Fig. 16: Mounting of the instrument with insulated vessels.
1 Electronics housing
2 Distance piece
3 Vessel insulation
Mounting in the vessel
insulation