Zero Trim; Sensor Trim - Emerson Rosemount 3051 Reference Manual

Reference Manual
00809-0100-4100, Rev AA
Sensor trim is a two-point sensor calibration where two end-point pressures are applied, and all
output is linearized between them. Always adjust the low trim value first to establish the correct
offset. Adjustment of the high trim value provides a slope correction to the characterization
curve based on the low trim value. The trim values allow you to optimize performance over your
specified measuring range at the calibration temperature.
During a trim operation, the 3051 Wireless is placed in high power refresh mode, which
provides frequent pressure measurement updates and allows the configured damping to take
effect. This behavior allows for more accurate calibration of the device. When the device is in
high power refresh mode, the battery power supply will be depleted more rapidly.
5.2.2

Zero Trim

Fast Keys
Note
The transmitter must be within three percent of true zero (zero-based) in order to calibrate with
zero trim function.
After properly venting the transmitter, calibrate the transmitter with the zero trim function:
1.
2.
3.
5.2.3

Sensor Trim

Fast Keys
Note
Use a pressure input source that is at least three times more accurate than the transmitter, and
allow the input pressure to stabilize for ten seconds before entering any values.
To calibrate the transmitter using the sensor trim function:
1.
2.
3.
4.
5.
6.
7.
Operation and Maintenance
2, 1, 3
From the Home screen, select 2: Configure.
Select 1: Guided Setup.
Select 3: Zero Trim and follow the on-screen instruction to complete the zero trim
adjustment.
3, 4, 1
Assemble and power the entire calibration system including the 3051, Field
Communicator/AMS, power supply, pressure input source, and readout device.
From the Home screen, select 3: Service Tools.
Select 4: Routine Maintenance.
Select 1: Sensor Calibration.
Select 4: Lower Sensor Trim. The lower sensor trim value should be the sensor trim
point that is closest to zero.
Follow the on-screen instructions to complete the adjustment of the lower value.
Repeat the procedure for the upper value. Select 5: Upper Sensor Trim and follow the
on-screen instructions to complete the adjustment of the upper value.
Section 5: Operation and Maintenance
June 2012
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