Diagnostics and troubleshooting
9.5 Treatment of measurement errors
Fault description
Cause
Rectification
Measured value remains
unchanged during filling
False signals in the close range too
big or level echo too small
Strong foam or vortex generation
Max. adjustment not correct
Eliminate false signals in the close
range
Check measuring point: Antenna
should protrude out of the threaded
mounting nozzle, possible 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 echo
suppression
Adapt max. adjustment
Measured value jumps
towards 0 % during filling
The level echo cannot be
distinguished from the false signal
at a false signal position (jumps to
multiple echo)
In case of interferences due to
installations in the close range:
Change polarisation direction
Chose a more suitable installation
position
Measured value jumps
towards 100 % during
filling
Due to strong turbulence and
foam generation during filling, the
amplitude of the level echo sinks.
Measured value jumps to false
signal
Carry out a auto false echo
suppression
Measured value jumps
sporadically to 100 %
during filling
Varying condensation or
contamination on the antenna
Carry out a auto false echo
suppression or increase auto
false echo suppression with
condensation/contamination in the
close range by editing
Measured value jumps to
≥ 100 % or 0 m distance
Level echo is no longer detected
in the close range due to foam
generation or false signals in the
close range. The transmitter goes
Check measuring point: Antenna
should protrude out of the threaded
mounting nozzle, possible false
echoes through flange nozzle?
SITRANS LR140
Operating Instructions, 08/2020,
A5E50352144
35
