Measurement Setup - Flow - Vega VEGAPULS 6X Operating Instructions Manual

5 Mounting
Mounting
Flume
42
•
A false signal suppression with the installed sensor is recom-
mended but not mandatory
•
The measurement through a ball valve with unrestricted channel
is possible
•
The deviation can increase in the area of the connecting tube to
the container ± 200 mm
Constructional requirements on the bypass pipe:
•
Material metal, smooth inner surface
•
In case of an extremely rough tube inner surface, use an inserted
tube (tube in tube) or a radar sensor with tube antenna
•
Flanges are welded to the tube according to the orientation of the
polarisation
•
Gap size with junctions ≤ 1 mm (for example, when using a ball
valve or intermediate flanges with single pipe sections)
•
Diameter should be constant over the complete length
5.7

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
•
Distance to the max. height of the orifice or flume for optimum
accuracy: > 250 mm (9.843 in)
•
Requirements from approvals for flow measurement, e.g.
MCERTS
Predefined curves:
A flow measurement with these standard curves is very easy to set
up, as no dimensional information of the flume is required.
•
Palmer-Bowlus flume (Q = k x h
•
Venturi, trapezoidal weir, rectangular flume (Q = k x h
•
V-Notch, triangular overfall (Q = k x h
Channel with dimensions according to ISO standard:
When selecting these curves, the dimensions of the flume must be
known and entered via the assistant. As a result, the accuracy of the
flow measurement is higher than with the specified curves.
•
Rectangular flume (ISO 4359)
•
Trapezoidal flume (ISO 4359)
•
U-shaped flume (ISO 4359)
•
Triangular overfall thin-walled (ISO 1438)
•
Rectangular flume thin-walled (ISO 1438)
•
Rectangular weir broad crown (ISO 3846)
The value given takes into account the block distance. At smaller distances,
7)
the measuring accuracy is reduced, see " Technical data".
7)
)
1.86
)
2.5
VEGAPULS 6X • Two-wire 4 ... 20 mA/HART
)
1.5