Emerson Rosemount 3144P, Reference Manual

Page: 194 / 236

Specifications and Reference Data
April 2017
Reference Manual
00809-0100-4021, Rev JA
Specifications and Reference Data
184
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 (
α
= 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

0.0015 °C/°C (30 °C–20 °C) = 0.015 °C
D/A effects (HART/4–20 mA only)

(0.001% /°C of span) |(ambient temp–calibrated
temp)|= D/A effects

(0.001% /f °C 100) |(30–20)| = 0.01 °C
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
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
Process temperature effects
Temperature effects example
When using a Pt 100 (
α
= 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
Type W5Re/W26Re
0.016 °C
0.023 °C + (0.0036% of T) T
≥
200 °C
T
<
200 °C
0.001% of span
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. Ambient temperature effect specification valid over minimum temperature span of 28 °C(50 °F).
3. Applies to HART/4–20 mA devices.
Sensor options
Digital accuracy per 1.0 °C (1.8 °F)
change in ambient
(1)(2)
Range D/A effect
(3)
0.10
2
0.02
2
0.015
2
0.01
2
+ + + 0.10
°
C =
Table A-2. Ambient and Process Temperature Difference Effect on Digital Accuracy
Sensor option
Sensor
reference
Effects per 1.0 °C(1.8 °F) difference in
ambient and process temperature
(1)
1. Valid under steady state process and ambient conditions.
Input temperature (T)
Rosemount X-well Pt 100 (
α
= 0.00385) IEC 751 ± 0.01 °C (0.018 °F) Entire sensor input range
0.0015
°
C
°
C
------ 30 20
°
C
– ( ) ×
0.015
°
C =
0.001%/
°
Cof span
[ ]
100
°
C 30 20
°
C
–
( ) × × °
C DA effect
=
0.001%/
°
C 100
× [ ]
30 20
–
( ) ×
0.001
°
C
=