Abstract: This disclosure is concerned with a novel technique for automatically fitting the output response characteristic curve of a measurement sensor to that of an ideal or reference sensor through determination of output variations in response to the same input stimulus near one end or point of the curve, storing the differences for automatic correction of the measurement sensor output by effectively superimposing the curves at such end, determination of output variations at another end or point of the curve, and effectively relatively pivoting the measurement sensor output curve about the said one end to cause substantial superposition of the other end or point of the curve and the span therebetween, thereby to provide stored signals for automatically correcting the output response of the measurement sensor, when in subsequent measurement use, over the complete characteristic response curve between its ends or selected points.