Vega VEGAFLEX 81 - Measurement error with constant level; Measurement error during filling

65
8 Diagnostics and service
VEGAFLEX 81 • Modbus and Levelmaster protocol
42283-EN-140430
Measurement error with constant level
Fault description Error pattern Cause Rectication
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
– Running time error (small
measurement error close to
100 %/serious error close to
0 %)
– Repeat setup
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 a false signal sup-
pression
– Amplitude or position of a
false signal has changed (e.g.
buildup); false signal suppres-
sion no longer matches
– Determine the reason for the
changed false signals, carry out
false signal suppression, e.g.
with buildup
Measurementerrorduringlling
Fault description Error pattern Cause Rectication
3. Measured value re-
mains in the area of the
bottomduringlling
Level
time
0
– Echo from the probe end larger
than the product echo, for
example, with products with
ε
r
< 2.5 oil-based, solvents, etc.
– Check parameter "Medium"
and "Vessel height", adapt if
necessary
4. Measured value re-
mains momentarily
unchangedduringll-
ing and then jumps to
the correct level
Level
time
0
– Turbulence on the product
surface,quicklling
– Check parameters, change if
necessary, e.g. in dosing ves-
sel, reactor
5. Measured value
jumps sporadically to
100%duringlling
Level
time
0
– Changing condensation or
contamination on the probe
– Carry out a false signal sup-
pression
6. Measured value
jumpsto≥100%or
0 m distance
Level
time
0
– Level echo is no longer
detected in the close range
due to false signals in the close
range. The sensor goes into
overllprotectionmode.The
max. level (0 m distance) as
well as the status message
"Overllprotection"areoutput-
ted.
– Eliminate false signals in the
close range
– Check installation conditions
– Ifpossible,switchothefunc-
tion"Overllprotection"