Figure 35 - Radar Impulse Reflection Model - Honeywell SLG 700 Option Manual

Reflection Models:
The radar impulse reflection model is an asymmetric damped cosine function that takes four
parameters as listed in the leftmost Reflection Models in above screen shot.
The model and its gain, width and attenuation parameters are illustrated in Figure
Go to section 3.6.5 for details on how to tune the parameters using HART DTM
Gain: This parameter determines the magnitude of the central peak of the damped cosine function.
Width: This parameter determines the width of the central lobe of the damped cosine function. It
approximately equals the width between the zero crossings of the function.
Attenuation: This parameter determines how fast the cosine wave is reduced to zero magnitude, and
therefore determines the height and width of the side lobes to either side of the central lobe. Increased
attenuation results in smaller side lobes. Note that the asymmetric property means that the side lobes
will each have a slightly different shape. This attenuation parameter should not be confused with the
medium attenuation that determines how the RADAR amplitude diminishes as it propagates down the
probe.
There are a total of 5 reflection models maintained by the transmitter to represent the types of
reflections that might be visible.
Reference
Process Connector
Surface
Interface
End Of Probe
The Reference reflection is a reflection caused by an impedance change where the transmission line
connects to the sensor board that generates the radar pulses. This reflection is always present and its
characteristic shape is not altered by any environmental or process conditions. In cases where the
sensor housing is directly connected to the process connector, the Reference reflection serves as an
internal datum point for locating the position of the transmitter's Reference Plane in the echo curve.
Rev.5

Figure 35 - Radar Impulse Reflection Model

FOUNDATION Fieldbus Option User's Manual
35.
Page 159