Thermistors. Part I. Static Characteristics
Otto J. M. Smith · Review of Scientific Instruments · 1950
The fundamental thermistor equations are presented as functions only of electrical quantities and constants, and independent of temperature measurements. The universal curves allow one to predict the static characteristics of thermistors as circuit elements. The two most significant characteristics are the power coefficient of resistance, and the negative incremental resistance. These can be computed, or read from the universal curves, if the resistance and four parametric constants are known. These five values can be determined from six convenient measurements: the resistance and change of resistance with current at very low current, at the maximum voltage point, and at maximum current.