Siemens SITRANS L Operating Instructions Manual page 41

Diagnostics and troubleshooting
9.4 Treatment of measurement errors
Fault description
Measured value jumps
sporadically to 100 %
during filling
Fault description
Measured value remains
unchanged in the close
range during emptying
Measured value jumps
sporadically towards
100 % during emptying
Measured value fluctuates
around 10 ... 20 %
34
Cause
Changing condensation or
contamination on the antenna
Cause
False signal greater than level echo
or level echo too small
Changing condensation or
contamination on the antenna
Various echoes from an uneven
medium surface, e.g. an extraction
funnel
Reflections from the medium
surface via the vessel wall
(deflection)
Rectification
Carry out a auto false echo
suppression or increase auto
false echo suppression with
condensation/contamination in the
close range by editing
Rectification
Eliminate false signals in the close
range. Check: Antenna must
protrude out of the nozzle
Remove contamination on the
antenna
Minimize interfering installations
in the close range by changing the
polarization direction
After eliminating the false signals,
the auto false echo suppression
must be deleted. Carry out a new
auto false echo suppression
Carry out auto false echo
suppression or increase auto false
echo suppression in the close range
by editing
Check parameter "Material Type"
and adapt, if necessary
Optimize installation position and
transmitter orientation
Operating Instructions, 12/2020, A5E49829013
SITRANS LR110