VEGA VEGAPULS 45 Profibus PA - Manual (Page 21)

VEGAPULS 42, 44 and 45 – Profibus PA 21
24908-EN-041227
Adhesive products
In non-adhesive or slightly adhesive prod-
ucts, use a surge pipe with a nominal width of
e.g. 50 mm. VEGAPULS 42 and 44 radar
sensors with 26 GHz technology are for the
most part insensitive to buildup in the meas-
uring tube. However, buildup should not
block the measuring tube.
For products with heavier buildup, the use of
a DN 80 to max. DN 100 standpipe or surge
pipe can make the measurement possible
despite buildup. But with extremely adhesive
products, measurement in a standpipe is not
possible at all.
Flange connections on bypass tubes
Seals on tube connections and tube ex-
tensions
Microwaves are very sensitive to gaps in
flange connections. If connections are made
without proper care, distinct false echoes as
well as increased signal noise can result.
Observe the following points:
• The applied seal should correspond to the
tube inner diameter.
• If possible, conductive seals such as con-
ductive PTFE or graphite should be used.
• There should be as few seal positions as
possible in the guide tube.
Guide tube in existing surge or bypass tubes
Extended guide tube
To increase the min. distance, the guide tube
can project out of the surge or bypass tube.
For this purpose, a plain flange can be
welded at the required position on the out-
side of the extended guide tube. In both
cases, a breather hole must be provided.
Guide tube
Mounting and installation