Emerson Process Management ROSEMOUNT 5300 - Manual (Page 25)

Reference Manual
00809-0100-4530, Rev BA
July 2009
2-11
Rosemount 5300 Series
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.
Coating Heavy coating of 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:
Table 2-3. Probe type guide for
different product viscosity
Maximum measurement error due to coating is 1-10% depending on probe
type, dielectric constant, coating thickness and coating 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.
Bridging Heavy product coating 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.
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.
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.
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.
Coaxial Twin Lead Single Lead
Maximum viscosity
500 cP 1500 cP 8000 cP (1)(2)
(1) Consult your local Emerson Process Management representatvie for agitation/turbulence and high
viscous products.
(2) Be precautious in HTHP viscous or crystallizing media applications where temperature at instrument
connection is significantly lower than process temperature with risk of coating in the upper part of
probe that may reduce the measurement signal. Consider using HP or STD probes in such
applications.
Coating/Build-up
Coating not recommended Thin coating allowed, but no
bridging
Coating allowed