50
BE 57-660 Eclipse Model 700 Guided Wave Radar Transmitter
Example 3:
Application calls for a 48-inch Model 7zT coaxial flanged
probe measuring water in a chamber with the bottom of
the probe extending six inches below the lower process
connection. The user wants the 4 mA point to
be 0 inches at the bottom process connection and the
20 mA point to be 30 inches at the top process connection.
3.4.2 End-of-Probe Analysis
A unique feature offered by the Model 700 ECLIPSE trans-
mitter is a feature called End-of-Probe Analysis (EoPA).
Located in the DEVICE SETUP/ADVANCED CONFIG
Menu, this feature is patterned after the “Tank-Bottom
Following” algorithms of the early Non-Contact radar
transmitters. When the return signal from the level is lost,
this feature allows the Model 700 transmitter to infer level
measurement based on the apparent location of the end-of-
probe (EoP) signal.
Due to the fact that the propagation of the GWR signal is
affected by the dielectric constant of the medium in which
it is traveling, signals along the probe are delayed in propor-
tion to the dielectric constant. By monitoring the location
of the (delayed) EoP signal and knowing the dielectric con-
stant of the medium, the level signal can be back-calculated,
or inferred.
The End-of-Probe Analysis feature is located in the
Advanced Config menu and requires an Advanced Password
to activate. Several additional parameters will need to be
configured for optimum performance.
NOTE: The accuracy of this level measurement mode is not that of
detecting true product level, and can vary depending on the
process. MAGNETROL recommends that this feature be used
only as last resort for measuring levels in those rare applica-
tions in which the level signals are inadequate, even after the
common troubleshooting techniques of gain increase and
threshold adjustment are implemented.
Refer to Section 4.0 “Advanced Configuration/
Troubleshooting Techniques” or contact MAGNETROL
Technical Support for additional instructions.
Example 3
20 mA
4 mA
15 cm
30 cm
Level Units = Centimeters
Probe Model = 7YG
Probe Mount = Flange
Probe Length = 75 cm
Level Offset = -15 cm
Dielectric Range =
Above 10
4 mA = 0 cm
20 mA = 30 cm
