The Platinum Resistance Thermometer BS EN60751:1996 standard specifies relationships for electrical resistance as a defined function of temperature.

The calculation finds either temperature, when resistance of the platinum resistance thermometer is known, or resistance when the temperature of the platinum resistance thermometer is known.

The calculation also presents the uncertainty in the calculation result based on the temperature and class of element.

References
British Standard BS1904:1984 Industrial Platinum Resistance Thermometer Sensors.