Emerson MMI-20019043 Manuel D’Utilisation

Excessive or erratic drive gain may indicate any of a variety of process conditions, sensor
problems, or configuration 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.

Slug flow

Check for slug flow. See 

Partially filled flow tube

Correct process conditions so that the flow tubes are full.

Plugged flow tube

). If either of them are

close to zero (but neither is zero), plugged tubes may be the source
of your problem. Purge the tubes. In extreme cases, you may need
to replace the sensor.

Cavitation, flashing, or air en-
trainment; settling of two- or
three-phase fluids

•

Increase the inlet or back pressure at the sensor.

•

If a pump is located upstream from the sensor, increase the dis-
tance between the pump and sensor.

•

The sensor may need to be reorientated. Consult the installa-
tion manual for your sensor for recommended orientations.

Drive board or module failure Contact Micro Motion.

Bent flow tube

). If either of them are

close to zero (but neither is zero), the flow tubes may be bent. The
sensor will need to be replaced.

Cracked flow tube

Replace the sensor.

Sensor imbalance

Contact Micro Motion.

Mechanical binding at sensor Ensure sensor is free to vibrate.

Open drive or left pickoff sen-
sor coil

Contact Micro Motion.

Flow rate out of range

Ensure that flow rate is within sensor limits.

Incorrect sensor characteriza-
tion

Verify the characterization parameters.

Wrong K1 characterization constant for sensor

Verify the K1 characterization parameter.

Troubleshooting

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