A NEW COMPENSATION SCHEME FOR THERMISTORS AND ITS IMPLEMENTATION FOR RESPONSE LINEARIZATION OVER A WIDE TEMPERATURE-RANGE

A new four-constant curve fit is proposed for the R-T characteristic o f a thermistor. That it provides a better fit than the two-constant la w R = Ae(B/T) is demonstrated by taking the examples of two standard c ommercial thermistors. A simple numerical method is suggested for dete rmining the constants of the new fit. Compared to other empirical rela tionships, the present equation lends itself to easy hardware lineariz ation. A temperature-to-frequency converter that has been developed em ploying the proposed fit is described. The converter is free from any error due to thermistor lead resistances, and provides an accuracy bet ter than 0.2 K over a temperature range from 300 K to 390 K.