VEGA VEGAMET 514… D - Manual (Page 28)

28 VEGAMET 514… D
Set-up, parameter adjustment
4.7.2 Flow measurement
General information
In the following section elementary information to dimensions in front of flumes, walls and sensor installation
positions is given.
Flume with meas. section (e.g. Khafagi-Venturi flume)
Fth meas. wall (e.g. rectangular weir)
Note
General
- h
max
is the max. damming or overflow height acc. to the meas. section or meas. wall.
- All other dimensions are nearly derived from h
max
(see above drawings)
Sensor mounting position
- Mount sensor on the inlet /upstream water side.
- Observe distance 3 - 4 x h
max
from sensor to the throat or meas. wall.
- Mount the ultrasonic and radar sensors centred to the flume and vertically to the flow medium.
- Consider with ultrasonic sensors the min. distance to hmax.
Meas. wall
- Dimension dependent on h
max
.
- Thickness on the meas. wall (horizontal part) k ≈ 3 mm.
- Swelling of the meas. wall with a transition of 45 ° (see above drawing).
- Distance from the opening of the meas. wall to downstream water ≤ 5 cm.
Top view
Lateral view
3 - 4 x h
max
Sensor
90 ° ≥ min. distance
of the sensor
h
max
Sensor
Inlet side Outlet side
Sensor
90 °
Sensor
h
max
≥ min. distance
of the sensor
3 - 4 x h
max
≥ 2 x h
max
90 °
Upstream water Downstream water
≥ 5 cm
k ≈ 3 cm
45 °
k ≈ 3 cm
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