A Derivation of a Universal Correction Function for the Magneto-resistance of a Newly Introduced Japanese Industrial Standard Platinum Resistance Thermometer GR 0705

Abstract

The magneto-resistance of three newly introduced Japanese Industrial Standard (JIS) platinum resistance thermometers, GR 0705, was studied. They were manufactured by a Japanese company, Hayashi Denko, and found to possess an excellent long term stability by our recent work. Their magneto-resistance was analyzed by the equation D(T)B²/(1+E(T)B) and its field dependence and temperature dependence were found to agree with each other. Following this observation, the universal functions for D(T) and E(T) were derived as a function of temperature between 20K and 240K. The resistance of the thermometer under magnetic field now can be represented by a simple analytic function of temperature and field strength of up to 8T. The error in the correction function was estimated by an independent experimental run. It reaches its maximum of 30mK at 20K and decreases as temperature rises. Above 40K the error is estimated to be as small as 10mK and dominated by an individuality of the sensors. The parameters, D(T) and E(T), are tabulated as a function of temperature.