Amplitude Tracking; Full-Tank Detection; Figure 2-4 Radar Impulse Reflection Model - Honeywell SLG 700 User Manual

Figure 2-4 Radar Impulse Reflection model

Although the algorithms are tolerant of signal amplitude variation, a good match is important
to discern the true level signal from that caused by obstacles near the probe or secondary
reflections. Both the DTM and the advanced display module show the signal quality, a
measure of the match between radar pulse model and acquired echo curve.

2.3.1 Amplitude Tracking

Release R102 introduced an additional feature in order to improve level tracking under
difficult conditions or when the medium attenuation is not well known. The amplitude
tracking feature (off by default) enhances the user specified pulse model information using
historical measurement data. It is able to improve the quality of the match when there are
slowly varying conditions in the tanks, such temperature variations, vapor density changed,
turbulence or even dirt build up on the probe. Amplitude tracking is not a substitute for model
tuning and will not track signals more than 35% different in amplitude from those expected.
It should be noted that tracked amplitudes are periodically saved to permanent memory.
When the sensor starts up it will first attempt to locate the levels using the tracked signal
amplitudes and if this fails, will revert to the initial amplitudes when the sensor loses power
since it is impossible to predict whether the conditions that caused the pulse to change (say
turbulence) exist when the sensor is repowered.

2.3.2 Full-tank Detection

This feature enables the transmitter to perform additional analysis on the data in the region
near the reference plane where the product reflections become mixed with reflections from
the physical mounting components such as a flange or nozzle. This additional analysis allows
the transmitter to detect the presence of product in this region even if the shape of the product
reflections deviate significantly from the expected shape. This option should only be enabled
if a recently captured Field or Obstacle background is in use and the Dielectric Constant of
the Upper Product is above 12. It should not be enabled for products with low Dielectric
Constants or when the Built-in background type is being used.
SLG 700 SmartLine Level Transmitter User's Manual
Revision 7 Page 19