VEGA VEGAPULS 67 (≥ 2.0.0 - ≥ 4.0.0) HART - integrated accumulator - Manual (Page 54)

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9 Diagnosis, Asset Management and service
VEGAPULS 67 • HART - integrated accumulator
40795-EN-121011
9.4 Measurement error with constant level
Fault description Error pattern Cause Rectification
1. Measured value
shows a too low or too
high level
Level
time 0
– Min./max. adjustment not
correct
– Adapt min./max. adjustment
– Wrong linearization curve – Adapt linearization curve
2. Measured value
jumps towards 100 % Level
time 0
– Due to the process, the ampli-
tude of the product echo sinks
– A false signal suppression was
not carried out
– Carry out false signal suppres-
sion
– Amplitude or position of a
false echo has changed (e.g.
condensation, buildup); false
signal suppression no longer
matches
– Determine the reason for the
changed false echo, carry out
false signal suppression, e.g.
with condensation
9.4 Measurement error during filling
Fault description Error pattern Cause Rectification
3rd measured val-
ue jumps towards 0 %
during filling
Level
time 0
– Amplitude of a multiple echo
(vessel top - product surface) is
larger than the level echo
– Check parameter "Application",
especially vessel top, product
type, dished end, high dielectric
figure, adapt if necessary
– The level echo cannot be distin-
guished from the false echo at
a false echo position (jumps to
multiple echo)
– Remove/reduce false echo:
minimize interfering installa-
tions by changing the polariza-
tion direction
– Chose a more suitable installa-
tion position
– Transverse reflection from an
extraction funnel, amplitude of
the transverse reflection larger
than the level echo
– Direct sensor to the opposite
funnel wall, avoid crossing with
the filling stream
4th measured val-
ue fluctuates around
10 … 20 %
Level
time 0
– Various echoes from an uneven
product surface, e.g. a material
cone
– Check application parameter
"Medium type" and adapt, if
necessary
– Optimize installation position
and sensor orientation
– Reflections from the product
surface via the vessel wall
(deflection)
– Select a more suitable installa-
tion position, optimize sensor
orientation, e.g. with a swivel-
ling holder
5. measured value
jumps sporadically to
100 % during filling
Level
time 0
– Varying condensation or con-
tamination on the antenna
– Carry out a false signal sup-
pression or increase false
signal suppression with con-
densation/contamination in the
close range by editing
– With bulk solids use radar sen-
sor with purging air connection
or flexible antenna cover