Endress+Hauser Levelflex FMP52, Operating Instructions Manual, Page: 125 / 198

Levelflex FMP55 HART Operating menu
Hauser 125
Additional information Meaning of the options
• Special: automatic DC
– Condition:
The specific capacitance (pF/m) is known.
7)
– Signal evaluation:
As long as a clear interface is detected, both the total and the interface level are
determined via the Guided Radar. The dielectric constant of the upper medium is
continuously adjusted. If an emulsion layer is present, the total level is determined via
the Guided Radar whereas the interface level is determined via the Capacitance
Measurement.
• Build up
– Condition:
The dielectric constant of the upper medium and the specific capacitance (pF/m) are
known.
7)
– Signal evaluation:
As long as a clear interface is detected, the interface level is determined via the Guided
Radar as well as via the Capacitance Measurement. If these two values start to diverge
from each other due to build-up formation, an error message is generated. If an
emulsion layer is present, the total level is determined via the Guided Radar whereas
the interface level is determined via the Capacitance Measurement.
• Standard
– Condition:
The dielectric constant of the upper medium is known.
– Signal evaluation:
As long as a clear interface is detected, the specific capacitance (pF/m) is continuously
adjusted. Therefore build-up has only little influence on the measurement. If an
emulsion layer is present, the total level is determined via the Guided Radar whereas
the interface level is determined via the Capacitance Measurement.
• Oil/Water condensate
– Condition:
The dielectric constant of the upper medium and the specific capacitance (pF/m) are
known.
7)
– Signal evaluation:
The total level is always determined via the Guided Radar. The interface level is always
determined via the Capacitance Measurement.
DC value lower medium 
Navigation  Setup → Advanced setup → Interface → DC lower medium
Prerequisite Operating mode (→  111) = Interface or Interface with capacitance
Description Specify the relative dielectric ocnstant ε
r
of the lower medium.
User entry 1 to 100
Factory setting 80.0
7) The specific capacitance of the media depends on the DC value and the geometry of the probe, which may differ noticeably. For rod probes < 2 m,
the probe geometry is measured after production and the resulting specific capacitance for conductive media is preset on delivery.