Honeywell SLG 700 User Manual page 115

10. Notice at previous step, the brown model line's amplitude is slightly larger than the
blue curve's amplitude. To reduce the model's amplitude to better match the blue
curve, decrease the Gain. By gradually decreasing Gain from 5122 to 3322 the
model more closely matches the blue curve while the Objective Function value has
improved from 0.658 to 0.580.
11. In the bottom graph of the Objective Function the red line indicates the Threshold.
The brown curve of the Objective Function must dip below this red Threshold line to
be recognized. If the Threshold is too low, increase its value to raise the red line
slightly above the dip as shown. Note that there should be only one dip that falls
below the Threshold line on the graph. If there are more than one, then the
transmitter may report incorrect position for the reflection. Recommended values of
the object function threshold are between 0.5 and 0.6. Higher values may cause
selection of the incorrect levels peaks. Lower values may not accommodate minor
pulse radar changes due to changing tank conditions.
12. In most cases changing the position, Gain, and occasionally Threshold should fix
any problems with the echo reading. Click Apply to save your changes.
Note:
Revision 5
Figure 25 Zoom View
TIP: By using the up and down arrows to increase and decrease Gain
you can home in on the lowest Objective Function value.
In this example, the model mismatch was exaggerated to better
illustrate the process. See step 14 for the final model parameters.
SLG 700 Series HART Option User's Manual
Page 107