Emerson Rosemount 8600 Series Reference Manual page 68

Operation
May 2019
Signal/trigger level ratio ( Sig/Tr)
FastKeys
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
FastKeys
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.
Manual filter adjust
FastKeys
Allows you to manually adjust the following settings: Low Flow Cutoff, Low Pass Filter, and
Trigger Level, while monitoring flow and or sig/tr.
Primary Variable (PV)
FastKeys
The actual measured variable. 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.
Signal/trigger level ratio (Sig/Tr)
FastKeys
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 that 4:1 will allow
increased filtering for noisy applications. For ratios greater than 4:1, with sufficient density,
the Optimize Flow Range 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.
60
1, 4, 3, 1, 3
1, 4, 3, 1, 4
1, 4, 3, 2
1, 4, 3, 2, 1
1, 4, 3, 2, 2
Reference Manual
00809-0100-4860, Rev BF
Rosemount 8600 Vortex Flow Meter