Selecting A Trim Procedure; Analog Output Trim - Emerson Rosemount 3051 Reference Manual

Operation and Maintenance
May 2017
4.3.2

Selecting a trim procedure

To decide which trim procedure to use, you must first determine whether the
analog-to-digital section or the digital-to-analog section of the transmitter electronics need calibration.
Refer to
1. Connect a pressure source, a Field Communicator or AMS Device Manager, and a digital readout
device to the transmitter.
2. Establish communication between the transmitter and the Field Communicator.
3. Apply pressure equal to the upper range point pressure.
4. Compare the applied pressure to the pressure process variable valve on the Process Variables menu on
the Field Communicator or the Process Variables screen in AMS Device Manager. For instructions on
how to access process variables, see
a. If the pressure reading does not match the applied pressure (with high-accuracy test
5. Compare the Analog Output (AO) line, on the Field Communicator or AMS Device Manager, to the
digital readout device.
If the AO reading does not match the digital readout device (with high-accuracy test equipment),
perform an analog output trim. See
4.4

Analog output trim

The analog output trim commands allow you to adjust the transmitter's current output at the 4 and
20 mA (1 and 5 Vdc) points to match the plant standards. This command adjusts the digital to analog
signal conversion.
Figure 4-2. Output Trim
A. Output trim
B. Characterization curve
68
Figure 4-1 and perform the following procedure:
equipment), perform a sensor trim. See
trim to perform.
A
B
page 15 of Section 2:
"Sensor trim overview" on page 71
"Analog output trim" on page
Reference Manual
00809-0100-4001, Rev KA
Configuration.
to determine which
68.
Operation and Maintenance