Calibration Frequency - Emerson Rosemount 3144P Reference Manual

Reference Manual
00809-0100-4021, Rev JA
3. Select 7 Diagnostics Suite.
4. Select 2 Config Min/Max Tracking.
5. Select 2 Disable to disable the Min/Max Tracking feature and select ENTER.
3.15 Calibration
Calibrating the transmitter increases the precision of the measurement system. The user may use one or
more of a number of trim functions when calibrating. To understand the trim functions, it is necessary to
realize that HART Protocol transmitters operate differently from analog transmitters. An important
difference is that smart transmitters are factory-characterized; they are shipped with a standard sensor
curve stored in the transmitter firmware. In operation, the transmitter uses this information to produce a
process variable output, dependent on the sensor input. The trim functions allow the user to make
adjustments to the factory-stored characterization curve by digitally altering the transmitter's
interpretation of the sensor input.
Calibration of the Rosemount 3144P may include:
Sensor input trim: Digitally alter the transmitter's interpretation of the input signal

Transmitter-sensor matching: generates a special custom curve to match that specific sensor curve, as

derived from the Callendar-Van Dusen (CVD) constants
Output trim: Calibrates the transmitter to a 4–20 mA reference scale

Scaled output trim: Calibrates the transmitter to a user-selectable reference scale

3.15.1

Calibration frequency

Calibration frequency can vary greatly depending on the application, performance requirements, and
process conditions. Use the following procedure to determine calibration frequency that meets the
needs of your application.
HART Commissioning
HART Commissioning
April 2017
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