Rosemount 5300 Series, Reference Manual

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15
Reference Manual
00809-0100-4530, Rev DD
Transmitter Overview
May 2016
Transmitter Overview
2.7 Process characteristics
The Rosemount 5300 Series has high sensitivity because of its advanced signal processing
and high signal to noise ratio. This makes it able to handle various disturbances, however,
the following circumstances should be considered before mounting the transmitter.
2.7.1 Contamination/product build-up
Heavy contamination or product build-up on the probe should be avoided since it may
decrease the sensitivity of the transmitter and lead to measurement errors. In viscous or
sticky applications, periodic cleaning may be required.
For viscous or sticky applications, it is important to choose a suitable probe. For detailed
information on the maximum recommended viscosity and coating, see
Table A-5 on
page 226 .
Maximum measurement error due to contamination is 1-10% depending on probe type,
dielectric constant, contamination thickness and contamination height above product
surface.
Signal Quality Metrics (SQM) diagnostic option can give an indication of how good the
surface signal is compared to the noise, and when to clean the probe.
2.7.2 Bridging
Heavy product build-up results in bridging between the two probes in a twin lead version,
or between the pipe and inner rod for coaxial probes, and may cause erroneous level
readings, so it must be prevented. A single lead probe is recommended in these situations.
2.7.3 Foam
The Rosemount 5300 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.
2.7.4 Vapor
In some applications, such as high pressure boiling water, there is a heavy vapor above the
product surface that could influence the level measurement. The Rosemount 5300 Series
Radar Transmitter can be configured to compensate for the influence of vapor.
2.7.5 Boiling hydrocarbons
For products with very low dielectric constants, such as boiling hydrocarbons and solids, the
threshold may need to be lowered, and/or the Probe End Projection (PEP) function
activated.