VEGA VEGASON 54P…56P Profibus PA - Manual (Page 19)

VEGASON 54P … 56P 19
≥
250 mm
Shaft pump
Measuring tube
Shaft pump
Socket piece
min.
distance
Meas. range
Measuring tube socket or measuring tube in a shaft
2.4 Measurement of solids
Flange mounting
For containers with solids, as with applica-
tions for liquids, the instrument can be
mounted on a short DIN socket piece. The
transducer end should protrude out of the
socket so that it does not interfere with ultra-
sonic signals. The swivelling holder enables
not only correct orientation to the product
surface but also minimisation of possible
false echoes.
Different filling conditions often lead to a vary-
ing product surface orientation. This causes
the useful echo to vary in quality. For this
reason, the transducer should be mounted in
such a way that, even in an empty vessel, the
false echo intensity remains as low as possi-
ble. You can view the echo curve on the PC
with the adjustment program VVO.
Mounting and installation
Pump shaft
Narrow, uneven shafts, wells and vessel
openings with very rough walls and shoul-
ders make ultrasonic measurements ex-
tremely difficult due to strong false echoes.
This problem can be overcome by using an
extended socket piece or a complete meas-
uring tube (see chapter "2.5 Socket exten-
sion").
VEGASON 54C with adapter flange on a DN 200
vessel flange
Reference plane
Min. distance
Shaft
Very good measuring results can be attained
with a measuring tube in continuous narrow
shafts, see illustration. The applied measur-
ing tube must have smooth walls inside (e.g.
PE sewage pipe) and a diameter
≥
200 mm.
This arrangement works well as long as the
inside of the measuring tube collects no dirt
or buildup (cleaning necessary). You might
want to consider using hydrostatic pressure
transmitters or capacitive measuring probes.
The measuring tube should either be never
immersed in the medium, or always im-
mersed, making the measurement take place
exclusively in the tube.
see "2.5 Socket extensions"