Vega VEGAPULS 64 - Measurement error during emptying

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9 Diagnosis, asset management and service
VEGAPULS 64 • Two-wire 4 … 20 mA/HART
51141-EN-210219
Fault description Cause Rectication
Measured val-
ue jumps towards
100%duringlling
Level
time
0
Due to strong turbulence and foam genera-
tionduringlling,theamplitudeofthelevel
echo sinks. Measured value jumps to false
signal.
Carry out a false signal suppression
Measured value
jumps sporadically to
100%duringlling
Level
time
0
Varying condensation or contamination on
the antenna.
Carry out a false signal suppression or
increase false signal suppression with con-
densation/contamination in the close range
by editing.
Measured value
jumpsto≥100%or
0 m distance
Level
time
0
Level echo is no longer detected at close
range due to foam generation or interfer-
ence signals at close range.
Check measuring point: Antenna should
protrude out of the threaded mounting sock-
et,possiblefalseechoesthroughange
socket.
Remove contamination on the antenna
Use a sensor with a more suitable antenna
Measurement error during emptying
Fault description Cause Rectication
Measured value re-
mains unchanged in
the close range dur-
ing emptying
Level
time
0
False signal larger than the level echo
Level echo too small
Eliminate false signal in the close range.
Check: Antenna must protrude from the
nozzle.
Remove contamination on the antenna
In case of interferences due to installations
in the close range: Change polarisation di-
rection
After eliminating the false signals, the false
signal suppression must be deleted. Carry
out a new false signal suppression.
Measured value
jumps towards 0 %
during emptying
Level
time
0
Echo from the tank bottom larger than the
level echo, for example, with products with
ε
r
< 2.5 oil-based, solvents
Check parameters Medium type, Vessel
height and Floor form, adapt if necessary
Measured value
jumps sporadically
towards 100 % dur-
ing emptying
Level
time
0
Varying condensation or contamination on
the antenna
Carry out false signal suppression or in-
crease false signal suppression in the close
range by editing.
With bulk solids, use radar sensor with
purging air connection.