Instrumentation & Calibration
Pt100 / IEC 60751
Convert between Pt100 resistance and temperature on the nominal IEC 60751 platinum characteristic. The selected thermometer tolerance class is shown separately from the nominal curve.
Field use
Nominal sensor check, not complete measurement uncertainty.
Use the nominal curve to compare a Pt100 element resistance against expected temperature during inspection, calibration or troubleshooting. Lead-wire resistance, transmitter accuracy, self-heating, thermowell effects and calibration uncertainty are separate contributors.
Calculation basis
IEC 60751 uses the Callendar–Van Dusen characteristic for the nominal platinum resistance/temperature relationship.
t < 0 °C: R(t) = R₀[1 + At + Bt² + C(t − 100)t³]
R₀: 100 Ω
A: 3.9083 × 10⁻³ °C⁻¹
B: −5.775 × 10⁻⁷ °C⁻²
C: −4.183 × 10⁻¹² °C⁻⁴, used below 0 °C
Tolerance classes are thermometer tolerances in °C and have construction-specific temperature ranges. They are not a substitute for the uncertainty specification of the complete sensor, wiring, transmitter and calibration system.