Emerson Micro Motion 9739 MVD, Руководство по конфигурации и использованию

Страница: 201 / 254

Troubleshooting
Tip
For typical applications, Micro Motion recommends setting Flow Cutoff to the zero stability of your sensor,
multiplied by 10.
10.24 Check for slug flow
The default slug flow limits are appropriate for most applications. Raising the low slug flow limit or
lowering the high slug flow limit will increase the possibility of the transmitter reporting slug flow
conditions.
If slug limits have been configured, and slug flow occurs, a slug flow alarm will be generated. Outputs
that are configured for flow rate hold their last known value until the slug flow clears, or up to the
configured slug flow duration, whichever comes first.
Procedure
1. Check whether slug flow alarms have been generated.
If the transmitter is not generating slug flow alarms, then slug flow is not the source of your problem.
2. Check the process for cavitation, flashing, or leaks.
3. Check the configured slug flow limits and duration.
A slug flow duration of 0.0 seconds will cause flow outputs to report zero flow as soon as slug
flow is detected. If you are experiencing slug flow alarms and no flow output, this maybe resolved
by increasing the slug flow duration.
Tip
The default high slug flow limit (5.0 g/cm 3 ) is appropriate for most applications.
4. Monitor the density output under normal process conditions.
It may be necessary to adjust the slug flow limits and duration to account for the normal density
variation in your process.
10.25 Check the drive gain
Collecting drive gain data
To know whether your drive gain is excessive or erratic, you must collect drive gain data during the
problem condition and compare it to drive gain data from a period of normal operation.
Configuration and Use Manual
195