Emerson Rosemount 2051G, Справочное руководство

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Reference Manual
00809-0400-4101, Rev BA
Operation and Maintenance
January 2018
Operation and Maintenance
Zero trim is a single-point offset adjustment. It is useful for compensating for mounting position effects
and is most effective when performed with the transmitter installed in its final mounting position. Since
this correction maintains the slope of the characterization curve, it should not be used in place of a
Sensor Trim over the full sensor range.
Note
Do not perform a zero trim on Rosemount 2051G Absolute Pressure Transmitters. Zero trim is zero
based, and absolute pressure transmitters reference absolute zero. To correct mounting position effects
on an Absolute Pressure Transmitter, perform a low trim within the sensor trim function. The low trim
function provides an offset correction similar to the zero trim function, but it does not require
zero-based input.
Upper and lower sensor trim is a two-point sensor calibration where two end-point pressures are applied,
all output is linearized between them, and requires an accurate pressure source. 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 help optimize
performance over a specific measurement range.
Figure 5-2. Sensor Trim Example
A. Before trim
B. After trim
5.5.2 Perform a sensor trim
When performing a sensor trim, both the upper and lower limits can be trimmed. If both upper and
lower trims are to be performed, the lower trim must be done prior to the upper time.
Note
Use a pressure input source that is at least four times more accurate than the transmitter, and allow the
input pressure to stabilize for 10 seconds before entering any values.
Field Communicator
From the HOME screen, enter the Fast Key sequence and follow the steps within the Field Communicator
to complete the sensor trim.
Device Dashboard Fast Keys
3, 4, 1
A
B
B
A