Resistance Change with Temperature
Resistance Change with Temperature
A metal’s resistance rises with temperature in proportion to its temperature coefficient — the basis of resistance thermometers.
The resistance is R = R_0·(1 + α·ΔT). where R_0 is the reference resistance, α the temperature coefficient and ΔT the temperature change.
Inputs
R_0 := 100 Ohm=100 Ω
alpha := 0.00385 K^-1=3.85e-03 1/K
dT := 50 K=50 K
Scale the reference resistance by the temperature term.
R := R_0·(1 + alpha·dT)=119.25 Ω
Results
A platinum RTD rises about 0.385 Ω per °C from 100 Ω — a near-linear, repeatable change that makes it an accurate thermometer.
Assumptions & limitations
- Linear temperature coefficient.
- Over a moderate range.
- Reference at 0 °C.