Emerson Rosemount 8800D Series Reference Manual page 95

Reference Manual
00809-0100-4772, Rev FA
Table 7-1. Basic Troubleshooting
Symptom Corrective action
No flow in pipe but
Basics
transmitter

indicates some
flow

Pipe/line vibration
In many cases if the Vortex transmitter indicates some flow when there is no actual flow,
it is due to pipe or line vibration. If there is obvious vibration, follow these recommenda-
tions:



50/60 Hz Measurement



Application Problems


Troubleshooting
www.aotewell.com
Check and verify configuration parameters in this order: K-factor, process fluid,
transmitter mode, fixed process temperature, fixed process density, density ratio,
pipe diameter, trigger level, low-flow cutoff, and low-pass corner frequency.
Check sizing; make sure the predicted flow is within the measurable flow limits.
Add support to the process piping as near the meter as possible. This will help to
dampen vibration at the meter.
If the vibration frequency is "in band" with the flow signal, it may be possible to
adjust the signal processing filters—specifically the "low flow cutoff" point—to ignore
the vibration.
Rotate the meter body 90 degrees.
Verify that no 50Hz or 60Hz interference is coupling in to the flow meter and being
interpreted as flow. Verify the remote sensor cable is properly earth grounded.
If the remote sensor cable runs near other cables carrying large AC currents, separate
the cables. The Vortex sensor cable should not be placed near other cables carrying
high current.
Lastly, if feasible, integrally mount the electronics to the meter body to see if the
problem goes away.
Verify any valve or valves in series with the meter are closed entirely.
Check if any pump pulsations are disturbing flow.
sales@aotewell.com
Industry Automation
Troubleshooting
March 2016
85
+86-755-8660-6182