Rosemount 5401, Справочное руководство

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Reference Manual
00809-0100-4026, Rev FA
July 2009
5-5
Rosemount 5400 Series
Pipe Diameter
When the transmitter is mounted in a still-pipe, the inner diameter of the pipe
must be specified. The Pipe Diameter is used to compensate for the lower
microwave propagation speed inside the pipe. An incorrect value gives a
scale factor error. If locally supplied still-pipes are used, make sure the inner
diameter is noted before the pipe is installed.
Transition Zone
The measurement accuracy is reduced within the Transition Zone region 6 in.
(150 mm) from the lower end of the antenna. It is recommended that the
Upper Range Value (20 mA) be set outside the Transition Zone, areas where
measurements are not recommended.
Process Conditions
Describe the conditions of the tank according to the Tank Environment
parameters for Process Conditions listed below. For best performance,
choose only if applicable,
and no more than two options
.
Rapid Level Changes
Optimize the transmitter for measurement conditions where the level changes
quickly from the filling and emptying of the tank. As a default standard, a 5400
transmitter is able to track level changes of up to 1.5 in./s (40 mm/s). When
the Rapid Level Changes check-box is selected, the transmitter can track
level changes of up to 8 in./s (200 mm/s).
Turbulent Surface
This parameter should be used if the tank has a turbulent surface. The reason
for the turbulence might be splash loading, agitators, mixers, or boiling
product. Normally, the waves in a tank are quite small and cause local rapid
level changes. By setting this parameter, the performance of the transmitter
will improve when there are small and quickly changing amplitudes and
levels.
Foam
Setting this parameter optimizes the gauge for conditions with weak and
varying surface echo amplitudes, such as foam. When the foam is light and
airy, the actual product level is measured. For heavy and dense foam, the
transmitter measures the level of the foam’s upper surface.
Product Dielectric Range
The Dielectric Constant is related to the reflectivity of the product. By setting
this parameter, measurement performance can be optimized. However, the
transmitter will still be able to perform properly, even if the actual Dielectric
Constant differs from the configured value.