Vega VEGAPULS 62 Operating Instructions Manual page 23

Flow measurement with
rectangular flume
VEGAPULS 62 • Foundation Fieldbus
Minimal amounts of stray radiation from the sensor can be reflected
and strengthened by the walls of the subsurface enclosures. In the
case of sensors with plastic housings, this can lead to coupling
disturbances. This is avoided by using a sensor with aluminium or
stainless steel housing.
Fig. 17: Mounting of the instrument in an subsurface enclosure
Subsurface enclosure
1
Concrete bottom
2
The short examples give you introductory information on the flow
measurement. Detailed planning information is available from flume
manufacturers and in special literature.
3 ... 4 h
max
90°
2
2
Fig. 18: Flow measurement with rectangular flume: d
sensor (see chapter "Technical data"); h
flume
Overflow orifice (side view)
1
Headwater
2
3 Tail water
Overfall orifice (view from bottom water)
4
In general, the following points must be observed:
1
≥ 50 mm
3
3
= max. filling of the rectangular
max.
4 Mounting
1 2
90°
4
= min. distance of the
min.
23