Siemens SITRANS L Series Operating Instructions Manual page 44

Measured value jumps towards
0 % during filling
Measured value jumps towards
100 % during filling
Measured value jumps sporadi-
cally to 100 % during filling
Measured value jumps to
≥ 100 % or 0 m distance
Measured value remains un-
changed in the close range dur-
ing emptying
SITRANS LR110
Operating Instructions, 01/2020, A5E49829006
Fault description
Fault description
11.5 Treatment of measurement errors
Cause
Max. adjustment not correct
The level echo cannot be distin-
guished from the false signal at
a false signal position (jumps to
multiple echo)
Due to strong turbulence and
foam generation during filling,
the amplitude of the level echo
sinks. Measured value jumps to
false signal
Varying condensation or conta-
mination on the antenna
Level echo is no longer detected
in the close range due to foam
generation or false signals in
the close range. The transmit-
ter goes into overfill protection
mode. The max. level (0 m dis-
tance) as well as the status mes-
sage "Overfill protection" are
output.
Cause
False signal larger than the level
echo
Level echo too small
Diagnostics and troubleshooting
Rectification
Check measuring point: Anten-
na should protrude out of the
threaded mounting nozzle, pos-
sible false echoes through flange
nozzle?
Remove contamination on the
antenna
In case of interferences due to
installations in the close range,
change polarisation direction
Create a new auto false each
suppression
Adapt max. adjustment
In case of interferences due to
installations in the close range:
Change polarisation direction
Chose a more suitable installa-
tion position
Carry out a auto false each sup-
pression
Carry out a auto false each sup-
pression or increase auto false
each suppression with conden-
sation/contamination in the
close range by editing
Check measuring point: Anten-
na should protrude out of the
threaded mounting nozzle, pos-
sible false echoes through flange
nozzle?
Remove contamination on the
antenna
Rectification
Check measuring point: Anten-
na should protrude out of the
threaded mounting nozzle, pos-
sible false echoes through flange
nozzle?
Remove contamination on the
antenna
In case of interferences due to
installations in the close range:
Change polarisation direction
39