Emerson Rosemount 2051 Reference Manual page 82

Operation and Maintenance
September 2020
operating points. Exercising the Transmitter over the desired pressure range allows for
verification of the analog output.
operations change the calibration. It is possible to degrade the performance of the
transmitter if a trim is done improperly or with inaccurate equipment. The transmitter can
be set back to factory settings using the
For transmitters that are field installed, the manifolds discussed in Rosemount 305, 306,
and 304 Manifolds allow the differential transmitter to be zeroed using the zero trim
function. Both 3-valve and 5-valve manifolds are discussed. This field calibration will
eliminate any pressure offsets caused by mounting effects (head effect of the oil fill) and
static pressure effects of the process.
Determine the necessary trims with the following steps.
Procedure
1. Apply pressure.
2. Check digital pressure, if the digital pressure does not match the applied pressure,
3. Check reported analog output against the live analog output. If they do not match,
5.4.4 Trimming with configuration buttons
Local configuration buttons are external buttons located underneath the top tag of the
transmitter. There are two possible sets of local configuration buttons that can be ordered
with the transmitter and used to perform trim operations: Digital zero trim and LOI. To
access the buttons, loosen screw and rotate top tag until buttons are visible.
• LOI (M4): Can perform both digital Sensor Trim and the 4–20 mA Output Trim (analog
output trim). Follow the same procedures listed in trimming with Field Communicator
or AMS Device Manager listed below.
• Digital zero trim (DZ): Used for performing a sensor zero trim. See
calibration frequency
All configuration changes should be monitored by a display or by measuring the loop
output.
Figure 5-1: Local Configuration Button Options
A. LOI - greeb retainer
B. Digital zero trim - blue retainer
82
perform a digital trim. See
perform an analog output trim. See
5 V output trim).
for trim instructions.
Figure 5-1 shows the physical differences between the two sets of buttons.
Trim the pressure signal
Recall factory trim—sensor
Perform a sensor trim .
Performing digital-to-analog trim (4–20 mA/1–
Reference Manual
00809-0100-4107
discusses how the trim
trim.
Determining
Rosemount 2051 Pressure Transmitter