Chapter 4 Theory of Operation
© National Instruments Corporation 4-7 SCXI-1503 User Manual
defined as the change in RTD resistance from 0 to 100 °C, divided by the
resistance at 0 °C, divided by 100 °C:
where
R100 is the resistance of the RTD at 100°C.
R0 is the resistance of the RTD at 0°C.
For example, a 100Ω platinum RTD with α = 0.003911 has a resistance of
139.11 Ω at 100 °C.
Figure 4-3 displays a typical resistance-temperature curve for a 100 Ω
platinum RTD.
Figure 4-3. Resistance-Temperature Curve for a 100Ω Platinum RTD, α = 0.00385
α(Ω/Ω/°C)R100 R0
–
R0100 °C×
-----------------------------=
480
400
320
240
160
80
320 400 480 560 640 720 800 8800 80 160 240 960