Study on NTC thermistor characteristic curve fitting methods

Thermistor characteristic equation directly determines the temperature measurement accuracy. Three fitting equation of NTC thermistors and their corresponding mathematic solutions are introduced. An adaptive algorithm based on cross-validation is proposed to determine the degree of chebyshev polynomials equation. The experiment indicates that the method of least squares for Steinhart-Hart equation and chebyshev polynomials equation has higher accuracy, and the equation determined by adaptive algorithm for the chebyshev polynomials method has better performance.