Emerson 8800C User Manual

Rosemount Model 8800C Vortex Flowmeter
3-20
Signal Processing The Model 8800C and its HART-based communications feature enable
you to filter out noise and other frequencies from the transmitter
signal. The four user-alterable parameters associated with the digital
signal processing on the Model 8800C include low-pass filter corner
frequency, low-flow cutoff, trigger level, and damping. These four signal
conditioning functions are configured at the factory for optimum
filtering over the range of flow for a given line size and service type
(liquid or gas). For most applications, leave these parameters at the
factory settings. Some applications may require adjustment of the
signal processing parameters.
Use signal processing only when recommended in the Troubleshooting
section of this manual. Some of the problems that may require signal
processing include:
• High output (output saturation)
• Erratic output with or without flow present
• Incorrect output (with known flow rate)
• No output or low output with flow present
• Low total (missing pulses)
• High total (extra pulses)
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 4: Hardware and Software Maintenance and
Troubleshooting procedures. 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
Optimize Flow Range affects the following variables:
• Flow
• Low Flow Cutoff
• Sig/Tr
• Auto Adjust Filter
Flow
Flow is the actual measured flow 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.
HART Comm. 1, 4, 4
HART Comm. 1, 4, 4, 1
HART Comm. 1, 4, 4, 1, 1
HART Comm. 1, 4, 4, 1, 2

Emerson 8800C Specifications

General

Brand	Emerson
Model	8800C
Category	Measuring Instruments
Language	English