Summary: Measuring Resistors
The following formulas occur in the chapter on measuring resistors as sensors:
\[
\begin{gathered}
R_{\mathrm{PT100}} = 100\,\Omega + 0.4\,\frac{\Omega}{°\mathrm{C}} \cdot T \\[6pt]
\text{Operation on a current source: } U_{\mathrm{PT100}} = R_{\mathrm{PT100}} \cdot I_0
\end{gathered}
\]