Rockwell Automation 1762-IR4 RTD/Resistance Input Module - Manual (Page 14)

Publication 1762-UM003A-EN-P - February 2003
1-4 Overview
The tables below provide specifications for RTD accuracy and
temperature drift.
Table 1.2 RTD Accuracy and Temperature Drift
RTD Type Maximum Scaled Accuracy
(25°C with Calibration)
Maximum Scaled Accuracy
(0 to 55°C with Calibration)
Maximum Temperature Drift
(from 25°C without
Calibration)
Copper 426 10
Ω
±0.6°C (1.08°F) ±1.1°C (1.98°F) ±0.032°C/°C (0.032°F/°F)
Nickel 618 120
Ω
±0.2°C (±0.36°F) ±0.4
°
C (±0.72°F) ±0.012°C/
°
C (±0.012°F/°F)
Nickel 672 120
Ω
±0.2°C (±0.36°F) ±0.4
°
C (±0.72°F) ±0.012°C/
°
C (±0.012°F/°F)
Nickel-Iron 518 604
Ω
±0.3°C (±0.54°F) ±0.5
°
C (±0.9°F) ±0.015°C/
°
C (±0.015°F/°F)
Platinum 385 100
Ω
±0.5°C (±0.9°F) ±0.9
°
C (±1.62°F) ±0.026°C/
°
C (±0.026°F/°F)
200
Ω
±0.5°C (±0.9°F) ±0.9
°
C (±1.62°F) ±0.026°C/
°
C (±0.026°F/°F)
500
Ω
±0.5°C (±0.9°F) ±0.9
°
C (±1.62°F) ±0.026°C/
°
C (±0.026°F/°F)
1000
Ω
±0.5°C (±0.9°F) ±0.9
°
C (±1.62°F) ±0.026°C/
°
C (±0.026°F/°F)
Platinum 3916 100
Ω
±0.4°C (±0.72°F) ±0.8
°
C (±1.44°F) ±0.023°C/
°
C (±0.023°F/°F)
200
Ω
±0.4°C (±0.72°F) ±0.8
°
C (±1.44°F) ±0.023°C/
°
C (±0.023°F/°F)
500
Ω
±0.4°C (±0.72°F) ±0.8
°
C (±1.44°F) ±0.023°C/
°
C (±0.023°F/°F)
1000
Ω
±0.4°C (±0.72°F) ±0.8
°
C (±1.44°F) ±0.023°C/
°
C (±0.023°F/°F)
IMPORTANT
Using Table 1.2 to Calculate Module Accuracy:
For example, when you are using any platinum (385)
RTDs with 0.5 mA excitation current, the module’s
accuracy is:
•
±0.5°C (0.9°F) after you apply power to the
module or perform an autocalibration at 25°C
(77°F) ambient, with module operating
temperature at 25°C (77°F).
•
±[0.5°C (0.9°F) ± DT x 0.026 deg./°C
(0.026 deg./°F)] after you apply power to the
module or perform an autocalibration at 25°C
(77°F) ambient, with module operating
temperature between 0 (32°F) and 55°C (131°F).
DT is the temperature difference between the
actual module operating temperature and 25°C
(77°F). The value 0.026 deg./°C (0.026 deg./°F) is
the temperature drift shown in the table above.
•
±0.9°C after you apply power to the module or
perform an autocalibration at 55°C (131°F)
ambient, with module operating temperature at
55°C (131°F).