Vega VEGAPULS 6X - Measurement setup - Flow

42
5 Mounting
VEGAPULS 6X • Two-wire 4 … 20 mA/HART
66190-EN-221107
•
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anges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umeandverticaltotheliquid
surface
•
DistancetotheoverfalloriceorVenturiume
•
Distancetothemax.heightoftheoriceorumeforoptimum
accuracy: > 250 mm (9.843 in)
7)
•
Requirementsfromapprovalsforowmeasurement,e.g.
MCERTS
Predenedcurves:
Aowmeasurementwiththesestandardcurvesisveryeasytoset
up,asnodimensionalinformationoftheumeisrequired.
•
Palmer-Bowlusume(Q=kxh
1.86
)
•
Venturi,trapezoidalweir,rectangularume(Q=kxh
1.5
)
•
V-Notch,triangularoverfall(Q=kxh
2.5
)
Channel with dimensions according to ISO standard:
Whenselectingthesecurves,thedimensionsoftheumemustbe
known and entered via the assistant. As a result, the accuracy of the
owmeasurementishigherthanwiththespeciedcurves.
•
Rectangularume(ISO4359)
•
Trapezoidalume(ISO4359)
•
U-shapedume(ISO4359)
•
Triangular overfall thin-walled (ISO 1438)
•
Rectangularumethin-walled(ISO1438)
•
Rectangular weir broad crown (ISO 3846)
Mounting
Flume
7)
The value given takes into account the block distance. At smaller distances,
the measuring accuracy is reduced, see " Technical data".