Sensor Trim - Emerson Rosemount 2051 Reference Manual

Reference Manual
00809-0100-4101
4.4

Sensor trim

4.4.1 Sensor trim overview
Trim the sensor using either sensor or zero trim functions. Trim functions vary in
complexity and are application-dependent. Both trim functions alter the transmitter's
interpretation of the input signal.
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.
When performing a zero trim, ensure that the equalizing valve is open and all wet legs are
filled to the correct levels.
NOTICE
Do not perform a zero trim on Rosemount 2051T Absolute pressure transmitters. Zero
trim is zero based, and absolute pressure transmitters reference absolute zero. To correct
mounting position effects on a 2051T 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.
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.
Figure 4-3: Sensor trim
4.4.2 Zero trim
Note
The transmitter must be within three percent of true zero (zero-based) in order to calibrate
with zero trim function.
Reference Manual
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March 2024
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