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57-642 ECLIPSE Model 705 Guided Wave Radar Transmitter for Hygienic Industries
4.4.4 Tuning/Optimization
GWR devices may require fine tuning in the field after
installation. In the most basic applications, the Model 705
requires no configuration or tuning. However, as complexi-
ties such as probe bending and proximity to disturbances in
the vessel are entered into design of the installation,
MAGNETROL suggests using the following guidelines to
tune a GWR unit.
4.4.4.1 Dielectric Range/Sensitivity
Adjust the Dielectric Range and Sensitivity parameters to
change the gain of the device. Dielectric range can be
thought of as a “course gain adjustment,” and sensitivity as
a “fine gain adjustment.” Often, there is no further configu-
ration or tuning required beyond these adjustments.
4.4.4.2 PACT
ware
Echo Curve
A HART modem is required for a PC to communicate with
the transmitter. Using the Echo Curve function provides a
real-time waveform and indicates the effects of the changes
made to configuration.
Threshold Adjustment Based on EchoCurve
There are cases where sensitivity adjustments will not ignore
noise present in a vessel. In those cases, threshold adjust-
ments (Positive or Negative depending on the Echo Curve)
may be necessary.
4.4.4.3 Blocking Distance
If there is noise at the top of the probe that can not be
ignored, such as an installation that is too close to a spray
ball that has an excessive flow stream aimed at the probe,
then an artificial dead-band can be introduced using the
"blocking distance" parameter. This is a top-down measured
portion of the probe that will be ignored.
4.4.4.4 Echo Curves in Dry and Filled States
Obtain Echo Curves in both dry and filled states to make
sure that changes to configuration do not affect the unit’s
ability to read the true end of probe signal as well as liquid
level along the probe.
