57
8 Diagnosis, asset management and service
LBR • Two-wire 4 … 20 mA/HART
62273-EN-200520
Measurement error during filling
Fault description
Cause
Rectification
Measured value
jumps towards 0 %
during filling
Level
time
0
Amplitude of a multiple echo (vessel top
- product surface) is larger than the lev-
el echo
Check parameter "Application", especially
vessel top, type of medium, dished bottom,
high dielectric constant, and adapt if nec-
essary.
The level echo cannot be distinguished from
the false signal at a false signal position
(jumps to multiple echo)
Remove/reduce false signal: minimize
interfering installations by changing the po-
larization direction
Chose a more suitable installation position
Transverse reflection from an extraction fun
-
nel, amplitude of the transverse reflection
larger than the level echo
Direct sensor to the opposite funnel wall,
avoid crossing with the filling stream.
Measured value
fluctuates around
10 … 20 %
Level
time
0
Various echoes from an uneven medium
surface, e.g. a material cone
Check parameter "Material Type" and
adapt, if necessary
Optimize installation position and sensor
orientation
Reflections from the medium surface via the
vessel wall (deflection)
Select a more suitable installation position,
optimize sensor orientation, e.g. with a swiv
-
elling holder
Measured value
jumps sporadically to
100 % during filling
Level
time
0
Changing condensation or contamination
on the antenna
Carry out a false signal suppression or
increase false signal suppression with con-
densation/contamination in the close range
by editing.
With bulk solids use radar sensor with purg-
ing air connection or flexible antenna cover.
Measurement error during emptying
Fault description
Cause
Rectification
Measured value re-
mains unchanged in
the close range dur-
ing emptying
Level
time
0
False signal larger than the level echo
Level echo too small
Eliminate false signals in the close range.
Check: Antenna must protrude out of the
socket.
Remove contamination on the antenna.
Minimize interfering installations in the close
range by changing the polarization direction.
After eliminating the false signals, the false
signal suppression must be deleted. Carry
out a new false signal suppression.
Measured value
jumps sporadically
towards 100 % dur-
ing emptying
Level
time
0
Changing condensation or contamination
on the antenna
Carry out false signal suppression or in-
crease false signal suppression in the close
range by editing.
With bulk solids use radar sensor with purg-
ing air connection or flexible antenna cover.
