Emerson Rosemount 3144P Reference Manual page 54

Reference Manual
00809-0100-4021, Rev AA
March 2002
Perform a sensor trim if the transmitters digital value for the primary variable
does not match the plant's standard calibration equipment. The sensor trim
function calibrates the sensor to the transmitter in temperature units or raw
units. Unless the site-standard input source is NIST-traceable, the trim
functions will not maintain the NIST-traceability of your system
.
Application: Linear Offset
Solution: Single-Point Trim
Method:
1. Connect sensor to transmitter. Place
sensor in bath between range points.
2. Enter known bath temperature using
the Model 275 HART Communicator.
One-Point Trim
Temperature
Transmitter System Curve
Site-Standard Curve
To perform a sensor trim, use the following procedure:
1. Disable Sensor 2.
a. Connect the communicator to the transmitter loop.
b. From the Home screen, select 1 Device setup, 3 Configuration, 2
Sensor Configuration, 1 Change Type/Conn, 2 Sensor 2.
c. Select OK after you set the control loop to manual.
d. Select Not Used at the "Enter Sensor 2 type" prompt.
e. Select OK at the "Sensor 2 connection set to: Not Used" prompt.
f. Select OK to return the control loop automatic control.
2. Connect the calibration device or sensor to the transmitter. Refer to
Figure 2-12 on page 2-16 or inside of the transmitter terminal side cover
for sensor wiring diagrams.
3. Connect the communicator to the transmitter loop.
4. From the Home screen, select 1 Device Setup, 2 Diag/Service,
2 Calibration, 1 Sensor Trim, 1 Sensor Inp Trim to prepare to trim the
sensor. Select 1 Sensor 1.
5. Set the control loop to manual and select OK. The communicator will ask
if an active calibrator is being used to perform the sensor trim. Select 1
Yes or 2 No.
6. Select the appropriate sensor trim units at the ENTER SNSR 1 TRIM
UNITS prompt.
Model 3144P
Application: Linear Offset and Slope Correction
Solution: Two-Point Trim
Method:
1. Connect sensor to transmitter. Place
sensor in bath at low range point.
2. Enter known bath temperature using the
Model 275 HART Communicator.
3. Repeat at high range point.
Two-Point Trim
Temperature
3-24