Emerson Rosemount 5408, Reference Manual

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Figure 2-2: Flowchart of the Signal Processing
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A. Microwave module
B. A/D converter
C. Fast Fourier transform (FFT)
D. Peak search
E. Peak interpolation
F. Echo tracker
G. Echo identifier
H. Distance filtering
I. Variable calculation
J. Aout handler
K. LCD handler
L. HART
®
2.2 Process characteristics
2.2.1 Dielectric constant
A key parameter for measurement performance is reflectivity. A high dielectric constant of
the media provides better reflection and enables a longer measuring range.
2.2.2 Foam and turbulence
Foaming liquids or turbulence may cause weak and varying surface echo amplitudes. The
effects of turbulence are usually minor, but in the most challenging conditions, the
transmitter may be mounted in a still pipe. In addition, measurement performance can be
optimized by configuring the appropriate process conditions settings.
Transmitter overview Reference Manual
February 2020 00809-0100-4408
12 Reference Manual