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Micro Motion Coriolis CMFHC4 with 5700R12 Transmitter Severe Two Phase issues

Hi, I urgently need some advice on an installation where a Coriolis sensor is used for flow and density measurement.

When flow is routed through the sensor an drive is reported to 100%. Severe two phase alarm and drive overrange is reported. There is no reliable measurement of flow.

I have done several smart meter verifications and they always pass.

When I do a verify zero, it fails. Then I calibrate new zero and the meter reports zero flow. If left alone for some time, it starts showing flow when there is no flow in the line. A new verify zero fails and a new calibrate zero is needed.

The system is designed for a maximum flow of 7500 L/min, so this might be to big for the task at hand.

I tried to contact support, but in my region only a sales representative was available and he could not help. Any help regarding this installation is appreciated.

  • And I may add that the flow will consist of either freshwater, seawater, brine or drilling mud with different densities. They will not be mixed, only one at a time.
  • In reply to Bjarte Haaland:

    Hello Bjarte, please send an email inquiry with these details to flow.support@emerson.com along with your phone number and email for a support technician to follow up with you directly. The high drive gain value is telling you there is an imbalance in the tubes - typically caused by bubbles or a partially-filled sensor, but can also be due to coating, scaling, erosion, or corrosion. The zero verification process first looks for process stability before sampling the current installed condition to verify if the current zero is valid. If the tubes are not full, or if the temperature or pressure change significantly between verifications, the zero verification test will fail. Please reach out to our support organization for more specific recommendations. Thanks.