Emerson Rosemount - 3.15.4 D;A output trim or scaled output trim; 3.15.5 Output trim

122
Reference Manual
00809-0100-4021, Rev GC
Section 3: HART commissioning
April 2014
HART® commissioning
Example for Rosemount 3144P Pt 100 ( = 0.00385)
Reference temperature is 20 °F
Process Temperature change is 0-100 °C
Ambient Temperature is 30 °C
1. Required Performance: ± 0.35 °C
2. TPE = 0.102 °C
a. Digital Accuracy = 0.10 °C
b. D/A Accuracy = (0.02%) x (30 – 20) °C = ±0.002 °C
c. Digital Temperature Effects = (0.0015 °C/ °C) x (30-20) °C = 0.015 °C
d. D/A Effect = (0.001%/ °C) x (100 °C) x (30-20) °C = 00.01 °C
e. Sensor Accuracy = ± 0.420 °C @ 400 °C for a class A RTD sensor with CVD constants
f. TPE =
3. Stability per Month: (0.25%/60 months) x (100 °C) = 0.00416 °C
4. Calibration Frequency:
3.15 Trim the transmitter
The trim functions should not be confused with the rerange functions. Although the rerange
command matches a sensor input to a 4–20 mA output—as in conventional calibration—it does
not affect the transmitter’s interpretation of the input.
One or more of the trim functions may be used when calibrating. The trim functions are as
follows:
 Sensor Input Trim
 Transmitter-Sensor Matching
 Output Trim
 Output Scaled Trim
0.1020.0022 0.0152 0.012 0.4202 ++++
= 0.102 °C
2
2
2
2
2
0.35 0.102–
0.00416
--------------------------------
= 60 Months (5 Years)