Rosemount 8800D Series User Manual

Reference Manual
00809-0100-4004, Rev BA
August 2010
Rosemount 8800D
4-16
Optimize Flow Range
The Optimize Flow Range function will automatically set the 8800D 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 that 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.
Manual Filter Adjust
Manual Filter Adjust allows you to manually adjust the following settings:
Low Flow Cutoff, Low Pass Filter, and Trigger Level, while monitoring flow
and or sig/tr.
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
Field Comm. 1, 4, 3, 2

Rosemount 8800D Series Specifications

General

Type	Vortex Flow Meter
Measurement Principle	Vortex Shedding
Operating Temperature	-40 to 185°F (-40 to 85°C)
Storage Temperature	-40 to 185°F (-40 to 85°C)
Communication Protocols	FOUNDATION Fieldbus
Material	316 stainless steel
Fluid Type	Liquid, Gas, Steam
Line Size	1/2 to 8 inches (15 to 200 mm)
Approvals	ATEX, IECEx, CSA, FM
Output Signal	4-20 mA
Process Connection	Flanged, Wafer, Threaded
Electrical Connection	M20
Protection Rating	IP66
Mounting Style	Wafer, Flanged