Abstract
Present situation of temperature measurement by means of platinum resistance thermometers below 0°C is described. After a short note on available equipment, the method of representating the relationship between the resistance and thermodynamic temperature is dealt with. Above the triple point of hydrogen, the extension of the International Practical Temperature Scale below 90°K and its improvement above 90°K are referred to, and a method of obtaining the temperature from a reference table such as CCT-64 and calibration at several thermometric fixed points, which has been proposed at the Comité Consultatif de Thermométrie, is described. Below the triple point of hydrogen down to helium temperatures, the resistance-temperature relationship of platinum is discussed.
