Endress+Hauser Levelflex FMP55, Operating Instructions Manual, Page: 87 / 214

Levelflex FMP55 HART Diagnostics and troubleshooting
Hauser 87
13.1.3 Parametrization errors
Parametrization errors for level measurements
Error Possible cause Remedial action
Measured value wrong If measured distance(Setup
→ Distance) matches the real
distance:
Calibration error • Check and adjust the Empty
calibration parameter (→  130) if
necessary.
• Check and adjust the Full calibration
parameter (→  131) if necessary.
• Check and adjust linearization if
necessary ( Linearization submenu
(→  149)).
If measured distance (Setup
→ Distance) does not match the real
distance:
An interference echo affects the
measurement. Perform mapping ( Confirm distance
parameter (→  135)).
No change of the measured
value when emptying/filling
the tank An interference echo affects the
measurement. Perform mapping ( Confirm distance
parameter (→  135)).
Build-up at the probe. Clean the probe.
Error in the echo tracking Deactivate echo tracking: Expert
→ Sensor → Echo tracking → Evaluation
mode =
History off ).
The diagnostic message
Echo lost appears after
switching on the supply
voltage.
Echo threshold too high. Check the Medium group parameter
(→  129).
If necessary select a more detailed
setting in the
Medium property
parameter.
Level echo suppressed. Delete mapping and record new
mapping curve if required (
Record map
parameter (→  137)).
Device displays a level when
the tank is empty. Incorrect probe length Carry out probe length correction
(
Confirm probe length parameter
(→  165)).
Interference echo Carry out mapping over entire probe
while the tank is empty (
Confirm
distance parameter (→  135)).
Wrong slope of the level in
the entire measuring range Wrong tank type selected. Set Tank type parameter (→  129)
correctly.
Parametrization errors for interface measurements
Error Possible cause Remedial action
Wrong slope of the measured
interface level Wrong dielectric constant (DC value). Enter the correct dielectric constant (DC
value) of the upper medium ( DC value
parameter (→  133)).
The measured values for the
interface and the total level
are identical Echo threshold for the total level too
high due to a wrong dielectric
constant. Enter the correct dielectric constant (DC
value) of the upper medium (
DC value
parameter (→  133)).
If the interface layers are
thin, the total level jumps to
the interface level. The thickness of the upper medium
is less than 60 mm (2.4 in). Interface measurement is only possible
if the thickness of the interface is
greater than 60 mm (2.4 in).