VEGA VEGAFLEX 61 4 … 20 mA_HART four-wire - Manual (Page 15)

S
tandpipes or bypass tubes are normally metal tubes with a diameter
of 30 … 200 mm (1.18 … 7.87 in). In measurement technology such a
tube corresponds to a coax probe. It does not matter if the standpipe is
perforated or slotted for better mixing. Lateral inlets with bypass tubes
also do not influence the measurement.
M easuring probes can be mounted in bypass tubes up to DN 200.
I f VEGAFLEX 61 is used in standpipes or bypass tubes, contact with
the tube wall should be avoided. We offer spacers as accessories for
fastening the probe in the middle of the tube.
D epending on the tube diameter or tube length, one or several spacers
can be mounted. With cable probes, the cable can also be strained to
avoid contact with the tube.
K eep in mind that buildup can form on the spacers. Strong buildup can
influence the measurement.
M icrowaves can penetrate plastics. For process technical reasons,
plastic standpipes are problematic. If durability is no problem, then we
recommend the use of metal standpipes.
1
Fig. 8: Position of the spacer
1 Spacer
Note:
M
easurement in a standpipe is not recommended for very adhesive
products.
Standpipes or bypass
tubes
VEGAFLEX 61 • 4 … 20 mA/HART four-wire 15
4 M ounting
31834
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EN
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