VEGA VEGAPULS 61 (≥ 2.0.0 - ≥ 4.0.0) 4 … 20 mA_HART - two-wire User Manual
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4 Mounting
VEGAPULS 61 • 4 … 20 mA/HART - two-wire
36499-EN-121011
•
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
The short examples give you introductory information on the flow
measurement. Detailed planning information is available from flume
manufacturers and in special literature.
h
ma
x
d
mi
n
≥ 2 mm x h
ma
x
90°
4
3 ... 4 h
max
≥ 50 mm
90°
2
3
1
Fig. 22: Flow measurement with rectangular flume: d
min.
= min. distance of the
sensor (see chapter "Technical data"); h
max.
= max. filling of the rectangular
flume
1 Overflow orifice (side view)
2 Headwater
3 Tail water
4 Overfall orifice (view from bottom water)
In general, the following points must be observed:
•
Install the sensor on the headwater side
•
Installation in the centre of the flume and vertical to the liquid
surface
•
Distance to the overfall orifice
•
Distance of orifice opening above ground
•
Min. distance of the orifice opening to bottom water
•
Min. distance of the sensor to max. storage level
Flow measurement with
rectangular flume