64
8 Diagnosis, asset management and service
VEGAPULS 69 • Modbus and Levelmaster protocol
47252-EN-210205
Measurement error with constant level
Fault description
Cause
Rectification
Measured value
shows a too low or
too high level
Leve
l
time
0
Min./max. adjustment not correct
Adapt min./max. adjustment
Incorrect linearization curve
Adapt linearization curve
Measured val-
ue jumps towards
100 %
Level
time
0
Due to the process, the amplitude of the
product echo decreases
A false signal suppression was not car-
ried out
Carry out a false signal suppression
Amplitude or position of a false signal has
changed (e.g. condensation, buildup); false
signal suppression no longer matches ac-
tual conditions
Determine the reason for the changed false
signals, carry out false signal suppression,
e.g. with condensation
Measurement error during filling
Fault description
Cause
Rectification
Measured value
jumps towards 0 %
during filling
Level
time
0
Amplitude of a multiple echo (vessel top
- medium surface) is larger than the lev-
el echo
Check parameter "Application", especially
vessel top, type of medium, dished bottom,
high dielectric constant, and adapt if nec-
essary.
The level echo cannot be distinguished from
the false signal at a false signal position
(jumps to multiple echo)
Remove/reduce false signal: minimize
interfering installations by changing the po-
larization direction
Chose a more suitable installation position
Transverse reflection from an extraction fun
-
nel, amplitude of the transverse reflection
larger than the level echo
Direct sensor to the opposite funnel wall,
avoid crossing with the filling stream.
Measured value
fluctuates around
10 … 20 %
Level
time
0
Various echoes from an uneven medium
surface, e.g. a material cone
Check parameter "Material Type" and
adapt, if necessary
Optimize installation position and sensor
orientation
Reflections from the medium surface via the
vessel wall (deflection)
Select a more suitable installation position,
optimize sensor orientation, e.g. with a swiv
-
elling holder
Measured value
jumps sporadically to
100 % during filling
Leve
l
time
0
Changing 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.
With bulk solids use radar sensor with purg-
ing air connection or flexible antenna cover.
