Rosemount 3051S - Sensor Trim Overview; Differential Pressure Sensor Calibration

90
Reference Manual
00809-0100-4803, Rev GA
Operation and Maintenance
September 2017
Operation and Maintenance
4.3.2 Sensor trim overview
Trim the sensors 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
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 with a manifold, refer to “Rosemount 305 and 304 Manifolds” on page 80.
Note
The transmitter must be within five percent or less of the maximum span of true zero (zero-based) in
order to calibrate with zero trim function.
The transmitter will not allow the user to perform a zero trim on an absolute static pressure sensor. To
correct mounting position effects on the absolute static pressure sensor, perform a lower sensor trim.
The lower sensor 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
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 lower sensor trim value first to establish the correct offset.
Adjustment of the upper sensor trim value provides a slope correction to the characterization curve
based on the lower sensor trim value. The trim values allow the user to optimize performance over a
specified measuring range at the calibration temperature.
4.3.3 Differential pressure sensor calibration
The Differential Pressure Calibration tab allows the user to complete a zero trim procedure or a full DP
sensor trim, see Figure 4-2 on page 91.
Mass and energy flow Fast Keys
1, 2, 5, 3
Direct process variable output Fast Keys
1, 2, 4, 3