Endress+Hauser Levelflex M FMP41C Interface Brief Operating Instructions page 27

Levelflex M FMP41C 4...20 mA HART
If the DC value is less than 7 for rope probes, then measurement is not possible in the area of
the tensioning weight (0 to 250 mm from end of probe; lower blocking distance).
Deviating from this, the following measured error occurs for thin interface layers (only
"K" interface measurement electronics version):
5.4.10 Function "Medium Property" (003)
ENDRESS + HAUSER
–
+
E
Use this function to enter the dielectric constant of the upper medium (upper phase).
Options:
• 2.00
The tables below split the DC values by product group. However, it is not sufficient to
assume a typical value. For accurate interface measurement, it is necessary to deter-
mine the DC of the upper medium (upper phase) as accurately as possible and enter
the value in this function.
The DC of the upper medium must be known and constant. The DC can be deter-
mined with the aid of the DC manual SD106F. In addition, it is also possible to calcu-
late the DC automatically in FieldCare if the interface thickness is available and
known.
Endress+Hauser
±50
±40
±30
±20
±10
0
thickness of upper medium
⇒
rod probe (example), also valid for coax probe
No measurement
upper
possible in
medium
this area
200 60
[mm]
Commissioning
lower medium
0
Interface
L00-FMP4xIxx-05-00-00-de-001
27