Emerson Micro Motion 1600 - 16.30 Check for two-phase flow (slug flow); 16.31 Check the sensor coils

Important
When sensor simulation is active, the simulated value is used in all transmitter outputs and calculations,
including totals and inventories, volume flow calculations, and concentration calculations. Disable all
automatic functions related to the transmitter outputs and place the loop in manual operation. Do not enable
simulation mode unless your application can tolerate these effects, and be sure to disable simulation mode
when you have finished testing. A power cycle will end sensor simulation.
16.30 Check for two-phase flow (slug flow)
Two-phase flow can cause rapid changes in the drive gain. This can cause a variety of measurement issues.
Procedure
1. Check for two-phase flow alerts (e.g., A105).
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. For
most liquid applications, leaving the Two-Phase Flow High Limit at 5.0 g/cc will suffice.
16.31 Check the sensor coils
Checking the sensor coils can identify a cause for a no sensor response alert.
Restriction
This procedure applies only to 9-wire remote-mount transmitters. For integral mount transmitters, consult the
factory.
Procedure
1. Disconnect power to the transmitter.
WARNING
If the transmitter is in a hazardous area, wait five minutes after disconnecting the power. Failure to
do so could result in an explosion causing death or injury.
2. Remove the wires from the sensor junction box.
3. Using a digital multimeter (DMM), check the pickoff coils by placing the DMM leads on the unplugged
terminal blocks for each terminal pair. See Table 16-7 for a list of the coils. Record the values.
Table 16-7: Coils and test terminal pairs
Coil Sensor model Terminal colors
Drive coil All Brown to red
Left pickoff coil (LPO) All Green to white
Right pickoff coil (RPO) All Blue to gray
Resistance temperature detector
(RTD)
All Yellow to violet
Configuration and Use Manual Troubleshooting
MS-00809-0200-1600 May2024
Configuration and Use Manual 219