Manual

l A false signal suppression with integrated sensor is recommended
but not mandatory
l The measurement through a ball valve with complete run is
possible
Constructional requirements on the bypass pipe:
l Material metal, smoother inner tube
l In case of an extremely rough tube inner surface, use an inserted
tube (tube in tube) or a radar sensor with tube antenna
l Flanges are welded to the tube according to the orientation of the
polarisation level
l Gap size with junctions ≤ 0.1 mm, for example, when using a ball
valve or intermediate flanges with single pipe sections
l The antenna diameter of the sensor should correspond to the
inner diameter of the tube
l 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
max
d
min
≥ 2 mm x h
max
90°
4
3 ... 4 h
max
≥ 50 mm
90
°
2
3
1
Fig. 20: 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:
l Install the sensor on the headwater side
l Installation in the centre of the flume and vertical to the liquid
surface
l Distance to the overfall orifice
l Distance of orifice opening above ground
l Min. distance of the orifice opening to bottom water
l Min. distance of the sensor to max. storage level
Fl
ow measurement with
rectangular flume
LEVEL TRANSMITTER 8136 • 4 … 20 mA/HART - two-wire 23
4 Mounting
41783-EN-120316