Abstract: An improved general purpose electronic thermometer comprising a platinum resistance sensor, a constant current source which impresses a current through said sensor, an amplifier which amplifies the voltage which results from the impressing of said current through said sensor--the resistance of which varies with temperature, an analog to digital converter which digitizes the signal from said amplifier and supplies the result to a microcomputer, said microcomputer which corrects for non-linearities in the resistance versus temperature relationship of the sensor using a ROM look-up table of corrections and an interpolation algorithm, and which outputs to a display either:the resulting temperature equivalent,a calculated rate of temperature change,a temperature equivalent representing the extreme of a temperature curve, defined as the temperature farthest removed from a determined initial temperature and in the direction of a determined initial significant change, derived by calculations and comparisons between c