Rosemount 5401, Reference Manual

Page: 20 / 180

Reference Manual
00809-0100-4026, Rev FA
July 2009
Rosemount 5400 Series
2-6
PROCESS
CHARACTERISTICS
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.
Foam
Rosemount 5400 Series Radar Transmitter measurement in foamy
applications depends on the foam properties; light and airy or dense and
heavy, high or low dielectrics, etc. If the foam is conductive and creamy, the
transmitter may measure the surface of the foam. If the foam is less
conductive, the microwaves may penetrate the foam, and measure the liquid
surface.
Turbulence
A calm surface gives better reflection than a turbulent surface. For turbulent
applications, the maximum range of the radar transmitters is reduced. The
range depends on the frequency, the antenna size, the dielectric of the
material, and the degree of turbulence. Consult Tables 2-1 and 2-2 on page
2-7 for the expected maximum range with the variables listed.
Temperature/Pressure/
Density and Vapor
Temperature, pressure, product density and vapor generally have no impact
on measurements.
Condensation
For applications where heavy condensation and vapors may occur, the low
frequency version Rosemount 5401 is recommended.
Tank Characteristics
The conditions inside the tank have a significant impact on measurement
performance. For more information see “Vessel Characteristics” on
page 3-12.