Convert Resistance to Temperature

Our calculator can convert resistance values to temperature for 100-ohm platinum resistance thermometers, at best it will agree with IEC-60751 values to the order of 0.01°C from -200°C to 850°C.

Calculate Temperature for Resistance Input

Temperature is calculated for the coefficient values shown below. You can enter calibration data to calculate custom coefficients and then use these values to convert ohms to Celsius, the resistance / temperature relationship is defined, for the range -200°C to 0°C Disclaimer

Rt=Ro[1 + At + Bt² + C(t-100°C) t³] and for the range 0°C to 850°C Rt=Ro(1 + At + Bt²)

Coefficients

Calculate Custom Probe Coefficients

Use either standard values from IEC-60751 (default), enter values or enter a probes calibration data to calculate values for a particular probe. For this form you need two suitable temperature / resistance points and either the resistance at 0°C or 0.01°C. Entering a third temperature, below 0°C will allow the C coefficient to be calculated. This is only used for temperatures less than 0°C and both T3/R3 and C can be ignored for temperatures above 0°C

Select Ro or Rwtp

Enter either Ro (Resistance at 0°C) or Rwtp (Water Triple Point Value) to match selection