Reference Manual
00809-0100-4022, Rev GA
September 2016
35
Section 4
Operation and Maintenance
Sensor trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 40
Recall factory trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 43
Analog output trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 44
4.1
Overview
This section contains information on operation and maintenance of the Rosemount
™
4600
Oil & Gas Pressure Transmitter.
Field Communicator and AMS
™
Device Manger instructions are given to perform
maintenance functions. For convenience, Field Communicator Fast Key sequences are
labeled “Fast Keys” for each software function below the appropriate headings.
4.2
Calibration for HART
®
protocol
Calibrating a transmitter may include the following procedures:
Rerange: Sets the 4 and 20 mA points at required pressures.
Sensor Trim: Adjusts the position of the factory characterization curve to optimize
performance over a specified pressure range, or to adjust for mounting effects.
Analog Output Trim: Adjusts the analog output to match the plant standard or the
control loop.
The Rosemount 4600 uses a microprocessor that contains information about the sensor’s
specific characteristics in response to pressure and temperature inputs. A smart transmitter
compensates for these sensor variations. The process of generating the sensor performance
profile is called factory characterization. Factory characterization also provides the ability to
readjust the 4 and 20 mA points without applying pressure to the transmitter.
Trim and rerange functions differ significantly. Reranging sets analog output to the selected
upper and lower range points and can be done with or without an applied pressure.
Reranging does not change the factory characterization curve stored in the microprocessor.
Sensor trimming requires an accurate pressure input and adds additional compensation
that adjusts the position of the factory characterization curve to optimize performance over
a specific pressure range.
Note
Sensor trimming adjusts the position of the factory characterization curve. It is possible to
degrade performance of the transmitter if the trim is done improperly or with inaccurate
equipment.
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