VEGA VEGAPULS 51K…54K 4 … 20 mA; HART compact sensor - Manual (Page 14)

14 VEGAPULS 51K … 54K
21750-EN-031222
Pipe antenna systems in the tank
Type label
Vent hole
ø 5 … 10 mm
Surge pipe welded
to the tank Surge pipe in the
socket piece
Surge pipes or bypass tubes which are
open at the bottom must extend over the full
measuring range (i.e. down to 0% level), as
measurement is only possible within the tube.
The tube inner diameter should be max.
100 mm or correspond to the size of the
antenna horn.
3.3 Measurement in standpipe
(surge or bypass tube)
General instructions
Measurement in a standpipe is preferred in
vessels which contain many installations, e.g.
heating tubes, heat exchangers or fast-run-
ning stirrers. Measurement is then possible
even when the product surface is very turbu-
lent, and vessel installations can cause no
false echoes.
Due to the concentration of radar signals in
the measuring tube, even products with small
dielectric constants (
ε
r
= 1.6 up to 3) can be
reliably measured in surge or bypass tubes.
Please observe the following installation di-
rections.
without deflector with deflector
Mounting and installation
As an alternative to socket mounting, the rod
antenna can also be mounted in round vessel
openings (threaded holes).
Rod antennas are available for the following
vessel openings: 1½“ NPT, DN 50 up to
DN 150. Keep in mind that the PTFE rod
antenna can only be subjected to very small
mechanical loads. If it is subjected to bend-
ing forces, deformation or even breakage will
occur.
Rod antenna with thread
When mounting the sensors with 1½“
screwed process connection in a socket
piece, the max. socket length must be ob-
served. The permissible socket length de-
pends on the antenna rod and is 50 mm,
100 mm or 250 mm, see also chapter „8.3
Dimensions“.
Rod antenna with thread on 1½“ socket
Rod antenna with thread on 1½“ thread hole
≤
50 mm or 100 mm or
250 mm
Reference plane
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min.
max.