Emerson Rosemount, Справочное руководство

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197
Reference Manual
00809-0100-4021, Rev GC
Appendix A: Reference Data
April 2014
Reference data
Transmitters may be installed in locations where the ambient temperature is between –40 and 85 °C
(–40 and 185 °F).
To maintain excellent accuracy performance, each transmitter is individually characterized over this
ambient temperature range at the factory.
Temperature effects example
When using a Pt 100 (

= 0.00385) sensor input with a 0 to 100 °C span at 30 °C ambient
temperature, the following statements would be true:
Digital temp effects
D/A effects (HART / 4–20 mA only)
Worst case error
D D/A + Digital Temp E D/A Effects = 0.10 °C + 0.02 °C + 0.015 °C + 0.01 °C
= 0.145 °C
Total probable error
GOST Type L 0.005 °C
0.005 °C + (0.003% of T)
T ³ 0 °C
T < 0 °C 0.001% of span
Millivolt Input 0.00025 mV Entire Sensor Input Range 0.001% of span
2-, 3-, 4-wire Ohm Input 0.007 ohms Entire Sensor Input Range 0.001% of span
(1) Change in ambient is in reference to the calibration temperature of the transmitter (20 °C [68 °F]).
(2) Applies to HART / 4-20 mA devices.
Sensor options
Digital accuracy per 1.0 °C (1.8 °F)
change in ambient
(1)
Range D/A effect
(2)
0.0015
C

C
-------
30

20

–
  
0.015

C =
°
0.001
%

C
------- x
Temperature Span x
(Amb Temp - Cal Temp)°
=DA Effect C
0.001
%

C
-------
x 100°C
x (30 - 20)°
C
°C DA Effect =
0.00001
°C
100°C
(30 - 20)° x =0.001°C DA Effect C
X
0.10
2
0.02
2
0.015
2
0.01
2
+ + +
0.10

C
=