S
tandpipes or bypass tubes are normally metal tubes with a diameter
of
30
…
200
mm
(
1
.
18
…
7
.
87
in
).
I
n measurement technology such a
tube corresponds to a coax probe
.
I
t does not matter if the standpipe is
perforated or slotted for better mixing
.
L
ateral inlets with bypass tubes
also do not in
fl
uence the measurement
.
M
easuring probes can be mounted in bypass tubes up to
DN
200
.
I
f
VEGAFLEX
62
is used in standpipes or bypass tubes
,
contact with
the tube wall should be avoided
.
W
e o
ff
er 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
.
W
ith 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
.
S
trong buildup can
in
fl
uence the measurement
.
F
or process technical reasons
,
plastic standpipes can always be used
.
H
owever
,
they o
ff
er no advantages for the measurement
.
I
f durability is
no problem
,
then we recommend the use of metal standpipes
.
1
F
ig
.
10
:
P
osition of the spacer
1
S
pacer
N
ote
:
M
easurement in a standpipe is not recommended for very adhesive
products
.
S
tandpipes or bypass
tubes
18
VEGAFLEX
62
•
4
…
20
m
A
/
HART
two
-
wire
4
M
ounting
31837
-
EN
-
090831