Range fractionation is a term used in biology. Sense organs are usually composed of many sensory receptors measuring the same property. These sensory receptors show a limited degree of precision due to an upper limit in firing rate. If the receptors are endowed with distinct transfer functions in such a way that the points of highest sensitivity are scattered along the axis of the quality being measured, the precision of the sense organ as a whole can be increased. This was shown for the chordotonal organ in the locust leg by Usherwood, Runion & Campbell (1968).
P. N. R. Usherwood and H. Runion and J. Campbell, Structure and physiology of a chordotonal organ in the locust leg, Journal of Experimental Biology, vol. 48, pp. 305--323, 1968.