37
10 Diagnostics and servicing
VEGAPULS C 11 • Two-wire 4 … 20 mA
58340-EN-200806
Liquids: Measurement error during filling
Fault description
Cause
Rectification
Measured value remains un-
changed during filling
Level
time
0
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
socket, possible false echoes through
flange socket?
Remove contamination on the antenna
In case of interferences due to instal-
lations in the close range, change
polarisation direction
Create a new false signal suppression
Adapt max. adjustment
Measured value jumps to-
wards 0 % during filling
Level
time
0
The level echo cannot be distinguished
from the false signal at a false signal po-
sition (jumps to multiple echo)
In case of interferences due to instal-
lations in the close range: Change
polarisation direction
Chose a more suitable installation po-
sition
Measured value jumps to-
wards 100 % during filling
Level
time
0
Due to strong turbulence and foam gen-
eration during filling, the amplitude of
the level echo sinks. Measured value
jumps to false signal
Carry out a false signal suppression
Measured value jumps spo-
radically to 100 % during
filling
Level
time
0
Varying condensation or contamination
on the antenna
Carry out a false signal suppression
or increase false signal suppression
with condensation/contamination in the
close range by editing
Measured value jumps to
≥ 100 % or 0 m distance
Leve
l
time
0
Level echo is no longer detected in
the close range due to foam genera-
tion or false signals in the close range.
The sensor 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
socket, possible false echoes through
flange socket?
Remove contamination on the antenna
