Emerson Rosemount - 4.10 Operation; 4.10.2 Trim the transmitter

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Reference Manual
00809-0100-4021, Rev GC
Section 4: FOUNDATION fieldbus Configuration
April 2014
Foundation™ fieldbus configuration
4.10 Operation
4.10.1 Overview
This section contains information on operation and maintenance procedures.
Methods and manual operation
Each FOUNDATION fieldbus host or configuration tool has different ways of displaying and
performing operations. Some hosts use DD Methods to complete device configuration and
display data consistently across platforms. There is no requirement that a host or configuration
tool support these features.
In addition, if your host or configuration tool does not support methods this section covers
manually configuring the parameters involved with each method operation. For more detailed
information on the use of methods, see the host or configuration tool manual.
4.10.2 Trim the transmitter
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. 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.
Figure 4-1. Trim
Application: Linear Offset Application: Linear Offset and
Slope Correction
Solution: Single-Point Trim Solution: Two-Point Trim
Method:
1.Connect sensor to transmitter. Place sensor in
bath between range points.
2.Enter known bath temperature using the field
communicator.
Method:
1.Connect sensor to transmitter. Place sensor in
bath at low range point.
2.Enter known bath temperature using the field
communicator.
3.Repeat at high range point.
One-Point Trim Two-Point Trim
Transmitter System Curve
Site-Standard Curve
Resistance (ohms)
Temperature
Resistance (ohms)
Temperature