Exchanging The Electronics Module - Siemens SITRANS LG250 Operating Instructions Manual

Measurement error during filling
Fault description
3. Measured value re-
mains in the area of the
bottom during filling
4. Measured value re-
mains momentarily
unchanged during fill-
ing and then jumps to
the correct level
5. Measured value
jumps sporadically to
100 % during filling
6. Measured value
jumps to ≥ 100 % or
0 m distance
Measurement error during emptying
Fault description
7. Measured value re-
mains unchanged in
the close range during
emptying
8. Measured value re-
mains reproducible
in one position during
emptying
Reaction after fault recti-
fication
68
Error pattern Cause
– Echo from the probe end larger
than the product echo, for
example, with products with
ε < 2.5 oil-based, solvents, etc.
r
0 time
– Turbulence on the product
surface, quick filling
0 time
– Changing condensation or
contamination on the probe
0 time
– 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
0
time
max. level (0 m distance) as
well as the status message
"Overfill protection" are output-
ted.
Error pattern Cause
– False signal larger than the
level echo
– Level echo too small
0
time
– Stored false signals in this
position are larger than the
level echo
0
time
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.
SITRANS LG250 - Operating Instructions
Rectification
– Check parameter "Medium"
and "Vessel height", adapt if
necessary
– Check parameters, change if
necessary, e.g. in dosing ves-
sel, reactor
– Carry out a false signal sup-
pression
– Eliminate false signals in the
close range
– Check installation conditions
– If possible, switch off the func-
tion "Overfill protection"
Rectification
– 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
– Delete false signal memory
– Carry out a new false signal
suppression
PBD-51041388