VEGA VEGAPULS 61 (≥ 2.0.0 - ≤ 3.8) 4 … 20 mA__HART four-wire - Manual (Page 22)

h m
ax
d m
in
≥
2
m
m
x
h m
ax
90°
4
3 ... 4 h
max
≥ 50 mm
90°
2 3
1
Fig. 17: Flow measurement with rectangular flume: d = min. distance of the
sensor; 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)
Khafagi-Venturi flume
I n general, the following points must be observed:
l I nstallation of the sensor at the inlet side
l I nstallation in the centre of the flume and vertical to the liquid
surface
l D istance to the Venturi flume
l M
in. distance of the sensor to max. storage level
2
3 ... 4 x h
max
90°
h
max
d
1 B
Fig. 18: Flow measurement with Khafagi-Venturi flume: d = Min. distance to
sensor; h
max.
= max. filling of the flume; B = tightest constriction in the flume
1 Position sensor
2 Venturi flume
22 VEGAPULS 61 • 4 … 20 mA/HART four-wire
4 M ounting
28439
-EN
-100426