Check For Radio Frequency Interference (Rfi); Check Hart Burst Mode; Check The Drive Gain - Emerson Micro Motion 4200 Configuration And Use Manual

Configuration and Use Manual
MMI-20048166
If the transmitter is not generating two-phase flow alerts, verify that two-phase flow limits have been
set. If limits are set, two-phase flow is not the source of your problem.
2. Check the process for cavitation, flashing, or leaks.
3. Monitor the density of your process fluid output under normal process conditions.
4. Check the settings of Two-Phase Flow Low Limit, Two-Phase Flow High Limit, and Two-Phase Flow
Timeout.
Tip
You can reduce the occurrence of two-phase flow alerts by setting Two-Phase Flow Low Limit to a
lower value, Two-Phase Flow High Limit to a higher value, or Two-Phase Flow Timeout to a higher
value.

15.27 Check for radio frequency interference (RFI)

The transmitter's Frequency Output or Discrete Output can be affected by radio frequency interference (RFI).
Possible sources of RFI include a source of radio emissions, or a large transformer, pump, or motor that can
generate a strong electromagnetic field. Several methods to reduce RFI are available. Use one or more of the
following suggestions, as appropriate to your installation.
Procedure
• Use shielded cable between the output and the receiving device.
— Terminate the shielding at the receiving device. If this is impossible, terminate the shielding at the
cable gland or conduit fitting.
— Do not terminate the shielding inside the wiring compartment.
— 360-degree termination of shielding is unnecessary.
• Eliminate the RFI source.
• Move the transmitter.

15.28 Check HART burst mode

HART burst mode is normally disabled, and should be enabled only if a HART Triloop is being used.
Procedure
1. Check to see if burst mode is enabled or disabled.
2. If burst mode is enabled, disable it.

15.29 Check the drive gain

Excessive or erratic drive gain may indicate any of a variety of process conditions or sensor problems.
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
Troubleshooting
April 2019
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