Check The Pickoff Voltage - Emerson Micro Motion 9739 MVD Configuration And Use Manual

Configuration and Use Manual
MMI-20016855
Important
You must trim the output at both ends (0 mA or 4 mA, and 20 mA to ensure that it is compensated accurately
across the entire output range.
Procedure
1. Choose Device Tools → Calibration → MA Output Trim → mA Output 1 Trim.
2. Choose Device Tools → Calibration → MA Output Trim → mA Output 1 Trim or Device Tools →
Calibration → MA Output Trim → mA Output 2 Trim.
3. Follow the instructions in the guided method.
4. Check the trim results. If any trim result is less than −20 microamps or greater than +20 microamps,
contact customer service.
10.20.2 Trim mA outputs using the Field Communicator
Trimming the mA Output establishes a common measurement range between the transmitter and the device
that receives the mA Output.
Prerequisites
Ensure that the mA Output is wired to the receiving device that will be used in production.
Important
You must trim the output at both ends (0 mA or 4 mA, and 20 mA to ensure that it is compensated accurately
across the entire output range.
Procedure
1. Follow the instructions in the guided method.
2. Choose Service Tools → Maintenance → Routine Maintenance → Trim mA Output 2.
3. Follow the instructions in the guided method.
4. Check the trim results. If any trim result is less than −20 microamps or greater than +20 microamps,
contact customer service.

10.21 Check the pickoff voltage

If the pickoff voltage readings are unusually low, you may have any of a variety of process or equipment
problems.
To know whether your pickoff voltage is unusually low, you must collect pickoff voltage data during the
problem condition and compare it to pickoff voltage data from a period of normal operation.
Drive gain and pickoff voltage are inversely proportional. As drive gain increases, pickoff voltages decrease
and vice versa.
Configuration and Use Manual
Troubleshooting
June 2019
151