Siemens SITRANS LR150 - Page 91

Diagnostics and troubleshooting
12.5Treatment of measurement errors
Fault description Cause Rectification
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
into overfill protection mode. The
max. level (0m distance) as well
as the status message " Overfill
protection" are output.
Check measuring point: Antenna
should protrude out of the threaded
mounting nozzle, possible false
echoes through flange nozzle?
Remove contamination on the
antenna
Fault description Cause Rectification
Measured value remains
unchanged in the close
range during emptying
False signal larger than the level
echo
Level echo too small
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
After eliminating the false signals,
the auto false echo suppression
must be deleted. Carry out a new
auto false echo suppression
Measured value jumps
sporadically towards
100% during emptying
Varying condensation or
contamination on the antenna
Carry out auto false echo
suppression or increase auto false
echo suppression in the close range
by editing
Fault description Cause Rectification
Min./max. adjustment not correct Adapt min./max. adjustmentMeasured value shows a
too low or too high level
Incorrect linearization curve Adapt linearization curve
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SITRANS LR150
Operating Instructions, 08/2020, A5E50352155