Measurement Setup - Flow - Vega VEGAPULS C 21 Operating Instructions Manual

4 Mounting
Rectangular overfall
16
4.5

Measurement setup - Flow

In general, the following must be observed while mounting the device:
•
Mounting the sensor on the upstream or inlet side
•
Installation in the centre of the flume and vertical to the liquid
surface
•
Distance to the overfall orifice or Venturi flume
•
Min. distance to the max. height of damming for optimum accu-
racy: 250 mm (9.843 in)
Detailed project planning data can be found at the channel manufac-
turers and in the technical literature.
The following examples serve as an overview for flow measurement.
3 ... 4 h
max
90°
2
2
Fig. 13: Flow measurement with rectangular flume: h
rectangular flume
1 Overfall orifice (side view)
2 Upstream water
3 Tailwater
4 Overfall orifice (view from tailwater)
At smaller distances the measuring accuracy is reduced, see "Technical
2)
data".
2)
1
3
3
max.
VEGAPULS C 21 • SDI-12
90°
4
= max. filling of the