Modeling the dependence of thermistor resistance on temperature

The results of a study on the accuracy of models describing the dependence of thermistor resistance on temperature are presented. The feasibility of using minimax (Chebyshev) approximation to calculate the model parameters is substantiated. Compared to the least squares method, the minimax approximation provides the smallest modeling error. A model in the form of an exponential function of a rational expression is proposed to describe the thermistor resistance as a function of temperature. The use of this model is based on considering the physical properties of the semiconductor resistance dependence on temperature. For the studied calibration results, the model recommended by the Consultative Committee for Thermometry (CCT) under the International Committee for Weights and Measures (CIPM) provides higher accuracy in describing the thermistor resistance--temperature dependence compared to the exponential of a rational expression. However, the accuracy of the model in the form of an exponential function of a rational expression is only slightly lower and practically comparable. Additionally, the model in the form of an exponential of a rational expression allows the use of temperature in the Celsius scale.