Rockwell Automation 1746-NR4 SLC RTD/Resistance Input Module User Manual - Manual (Page 15)

Publication 1746-UM008B-EN-P - December 2006
Overview 15
When you are using 100
Ω or 200 Ω platinum RTD units with 0.5 mA
excitation current, refer to the following important information about
module accuracy.
IMPORTANT
Module accuracy, using 100 Ω or 200 Ω platinum RTD units with 0.5 mA
excitation current, depends on the following criteria:
• Module accuracy is ±0.6 °C (±33.08 °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).
• Module accuracy is ±(0.6 °C + ΔT x 0.034 °C/°C) or
±(33.08 °F + ΔT x 32.06 °F/°F) after you apply power to the module or
perform an autocalibration at 25 °C (77 °F) ambient with the module
operating temperature between 0…60 °C. (32…140 °F).
Where
ΔT is the temperature difference between the actual
operating temperature of the module and 25 °C (77 °F) and
0.034 °C/°C (32.06 °F/°F) is the temperature drift shown in the table
above for 100
Ω or 200 Ω platinum RTD units.
Module accuracy is ±1.0 °C (±33.80 °F) after you apply power to the
module or perform an autocalibration at 60 °C (140 °F) ambient with
module operating temperature at 60 °C (140 °F).