Siemens SITRANS LG250, Руководство по эксплуатации, Страница: 68 / 92

68 PBD-51041388 SITRANS LG250 - Operating Instructions
46201-EN-150424
Measurement error during filling
Fault description Error pattern Cause Rectification
3. Measured value re -
mains in the area of the
bottom during filling
Level
time
0
– Echo from the probe end larger
than the product echo, for
example, with products with
ε
r
< 2.5 oil-based, solvents, etc.
– Check parameter "Medium"
and "Vessel height", adapt if
necessary
4. Measured value re -
mains momentarily
unchanged during fill -
ing and then jumps to
the correct level
Level
time 0
– Turbulence on the product
surface, quick filling
– Check parameters, change if
necessary, e.g. in dosing ves-
sel, reactor
5. Measured value
jumps sporadically to
100 % during filling
Level
time 0
– Changing condensation or
contamination on the probe
– Carry out a false signal sup-
pression
6. 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 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 -
ted.
– Eliminate false signals in the
close range
– Check installation conditions
– If possible, switch off the func -
tion "Overfill protection"
Measurement error during emptying
Fault description Error pattern Cause Rectification
7. Measured value re -
mains unchanged in
the close range during
emptying
Level
time 0
– False signal larger than the
level echo
– Level echo too small
– Eliminate false signals in the
close range
– Remove contamination on the
probe. After having removed
the source of the false signals,
the false signal suppression
must be deleted.
– Carry out a new false signal
suppression
8. Measured value re -
mains reproducible
in one position during
emptying
Level
time
0
– Stored false signals in this
position are larger than the
level echo
– Delete false signal memory
– Carry out a new false signal
suppression
Depending on the reason for the fault and the measures taken, the
steps described in chapter " Set up " may have to be carried out again.
10.5 Exchanging the electronics module
If the electronics module is defective, it can be replaced by the user.
With SIL qualified instrument, only a respective electronics module
with SIL qualification must be used.
In Ex applications, only instruments and electronics modules with ap-
propriate Ex approval may be used.
Reaction after fault recti -
fication