Siemens SITRANS L Series Operating Instructions Manual page 39

Diagnostics and troubleshooting
9.5 Treatment of measurement errors
Measured value jumps sporadi-
cally towards 100 % during emp-
tying
Measured value shows a too low
or too high level
Measured value jumps towards
100 %
Measured value jumps towards
0 % during filling
34
Fault description
Fault description
Fault description
Cause
Varying condensation or conta-
mination on the antenna
Cause
Min./max. adjustment not cor-
rect
Incorrect linearisation curve
Due to the process, the ampli-
tude of the product echo de-
creases
A auto false echo suppression
was not carried out
Amplitude or position of a false
signal has changed (e.g. conden-
sation, buildup); auto false echo
suppression no longer matches
actual conditions
Cause
The level echo cannot be distin-
guished from the false signal at
a false signal position (jumps to
multiple echo)
Rectification
After eliminating the false sig-
nals, the auto false echo sup-
pression must be deleted. Carry
out a new auto false echo sup-
pression
Carry out auto false echo sup-
pression or increase auto false
echo suppression in the close
range by editing
Rectification
Adapt min./max. adjustment
Adapt linearisation curve
Carry out a auto false echo sup-
pression
Determine the reason for the
changed false signals, carry out
auto false echo suppression, e.g.
with condensation.
Rectification
Remove/reduce false signal: min-
imize interfering installations by
changing the polarization direc-
tion
Chose a more suitable installa-
tion position
SITRANS LR100
Operating Instructions, 01/2020, A5E49829004