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Reference Manual
00809-0100-4860, Rev BC
Section 4: Operation
January 2013
Operation
If one or more of these conditions exist, and you have checked other potential sources (K-factor,
service type, lower and upper range values, 4–20mA trim, pulse scaling factor, process
temperature, pipe ID), refer to Section 5: Troubleshooting. Remember that the factory default
settings can be re-established at any time with Filter Restore. If problems persist after signal
processing adjustments, consult the factory.
Optimize flow range
The Optimize Flow Range function will automatically set the 8600D filter levels, Low Flow Cutoff
(LFC), Trigger Level, and Low Pass Corner Frequency, to optimum settings based on the process
density and process fluid type.
Primary Variable (PV)
PV is the actual measured variable rate in the line. On the bench, the PV value should be zero.
Check the units on the PV to make sure they are configured correctly. See PV Units if the units
format is not correct. Use the Process Variable Units function to select the units for
your application.
Low flow cutoff
Low Flow Cutoff is shown in engineering units.
Signal/trigger level ratio (Sig/Tr)
The Signal to Trigger Level Ratio is a variable that indicates the flow signal strength to trigger
level ratio. This ratio indicates if there is enough flow signal strength for the meter to work
properly. For accurate flow measurement, the ratio should be greater than 4:1. Values greater
than 4:1 will allow increased filtering for noisy applications. For ratios greater than 4:1, with
sufficient density, the Auto Adjust Filter function can be utilized to optimize the measurable
range of the flowmeter.
Ratios less than 4:1 may indicate applications with very low densities and/or applications with
excessive filtering.
Auto adjust filter
The Auto Adjust Filter is a function that can be used to optimize the range of the flowmeter
based on the density of the fluid. The electronics uses process density to calculate the minimum
measurable flow rate, while retaining at least a 4:1 signal to the trigger level ratio. This function
will also reset all of the filters to optimize the flowmeter performance over the new range. For a
stronger signal select a density value that is lower than the actual flowing density.
Field Comm. 1, 4, 3, 1
Field Comm. 1, 4, 3, 1, 1
Field Comm. 1, 4, 3, 1, 2
Field Comm. 1, 4, 3, 1, 3
Field Comm. 1, 4, 3, 1, 4