An RTD forms one arm of an equal-arm Wheatstone bridge, as shown in Figure 8.8. The fixed
resistances, R2 and R3 are equal to 25 V. The RTD has a resistance of 25 V at a temperature of 0C
and is used to measure a temperature that is steady in time.
The resistance of the RTD over a small temperature range may be expressed, as in Equation 8.5:
RRTD ¼ R0½ 1 þ að Þ T T0