Rosemount 5600 Series, Справочное руководство

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Reference Manual
00809-0100-4024, Rev BA
September 2005
Rosemount 5600 Series
4-18
Filtering
Distance Filter Factor The Distance Filter Factor defines how much the level value
should be filtered. A low factor setting will give the new level
value by adding a small portion (for instance 1%) of the level
change to the previous level value. A high factor setting
typically takes the latest measurement and presents it as the
new level. This implies that a low factor setting makes the level
value steady but the transmitter reacts slower to level changes
in the tank. A high factor setting makes the transmitter react
quickly to level changes but the level value can be somewhat
jumpy.
Activate Jump Filter If the surface echo is lost and a new surface echo is found, the
Jump Filter tells the transmitter to wait for some time before it
jumps to the new echo. During that time the new echo has to be
a valid echo. The Jump Filter does not use the Distance Filter
Factor and can be used in parallel to the Least Square Filter or
the Adaptive Filter. The Jump Filter is typically used for
applications with turbulent surface and makes the echo
tracking work smoother as the level passes the agitator.
Activate Least Square Filter This filter calculates the new level value according to the least
square method and will give increased accuracy for slow filling
or emptying of tanks. The level value will follow the surface with
high accuracy and without delay as the level changes. When
the level stabilizes at a certain level, the Least Square Filter
makes the level move somewhat further before it aligns to the
correct level value.
Activate Adaptive Filter The Adaptive Filter is tracking the level fluctuations, and is
continuously adjusting the filter grade accordingly. The filter can
preferably be used in tanks where fast tracking of level changes
are important, but where turbulence occasionally cause
unstable level values.