Emerson Process Management 5300 manual Process Characteristics, Coating

Reference Manual

00809-0100-4530, Rev BA July 2009

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

Coaxial	Twin Lead	Single Lead
	Maximum viscosity
500 cP	1500 cP	8000 cP(1)(2)
	Coating/Build-up
Coating not recommended	Thin coating allowed, but no	Coating allowed
	bridging

Bridging

Foam

Vapor

Boiling Hydrocarbons

(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.

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.

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.

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.

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.

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.

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