Position measuring device with magnetostrictive technology comprising a magnetostrictive sensor with: a magnetostrictive wave guide; at least one magnetic cursor sliding along said wave guide; a pulse generator (25, 25') associated with the wave guide, for supplying said magnetostrictive sensor with current pulses (Po) and producing a magnetostrictive effect in correspondence with said magnetic cursor; a magnetoacoustic wave detector placed at one end of said wave guide for detecting echoes of said pulses (Po) and outputting a corresponding detection electric signal (Vb); said pulse generator (25, 25') being driven for generating pulses with period equal to at least a multiple on basis 2 of time t L, where time t L is the time used by a magnetoacoustic wave to go through said length of said wave guide, so that the secondary echoes of a given excitation pulse (k) are in constructive interference with the main echo of an immediately successive excitation pulse (k+1), said pulse generator (25, 25') generating a first excitation pulse (k) which produces a magnetostrictive signal in correspondance with said mobile magnet, said magnetostrictive signal developing in both directions of said wave guide with a first main echo (e 1s) and a first secondary echo (e 1d) which respectively propagate in the direction of said end of said guide and of an opposite end producing in turn second and third secondary echoes (e 2s, e 2d) by reflection which are in constructive interference with the main echoes of the immediately successive excitation pulse (k+1), said detector defining at least one pair of receipt times t e1s, t e2s respectively of said first main echo e 1s and of a secondary echo e 2s generated by reflection in both the ends of e 1s and/or at least one pair of receipt times t e1d, t e2d respectively of a first secondary echo e 1d and of an echo e 2d generated by reflection, said position measuring device being arranged to calibrate said detector allowing a compensation of a shift of said detector from an origin end, said shift being defined in a end temporal value α and taken from calculation means according to any of the following relations: t e 1 s + t e 1 d = 2 t L + 2 α t e 2 s + t e 1 d = 4 t L + 2 α t e 2 s + t e 2 d = 6 t L + 2 α a magnetostrictive wave guide; at least one magnetic cursor sliding along said wave guide; a pulse generator (25, 25') associated with the wave guide, for supplying said magnetostrictive sensor with current pulses (Po) and producing a magnetostrictive effect in correspondence with said magnetic cursor; a magnetoacoustic wave detector placed at one end of said wave guide for detecting echoes of said pulses (Po) and outputting a corresponding detection electric signal (Vb); said pulse generator (25, 25') being driven for generating pulses with period equal to at least a multiple on basis 2 of time t L, where time t L is the time used by a magnetoacoustic wave to go through said length of said wave guide, so that the secondary echoes of a given excitation pulse (k) are in constructive interference with the main echo of an immediately successive excitation pulse (k+1), said pulse generator (25, 25') generating a first excitation pulse (k) which produces a magnetostrictive signal in correspondance with said mobile magnet, said magnetostrictive signal developing in both directions of said wave guide with a first main echo (e 1s) and a first secondary echo (e 1d) which respectively propagate in the direction of said end of said guide and of an opposite end producing in turn second and third secondary echoes (e 2s, e 2d) by reflection which are in constructive interference with the main echoes of the immediately successive excitation pulse (k+1), said detector defining at least one pair of receipt times t e1s, t e2s respectively of said first main echo e 1s and of a secondary echo e 2s generated by reflection in both the ends of e 1s and/or at least one pair of receipt times t e1d, t e2d respectively of a first secondary echo e 1d and of an echo e 2d generated by reflection, said position measuring device being arranged to calibrate said detector allowing a compensation of a shift of said detector from an origin end, said shift being defined in a end temporal value α and taken from calculation means according to any of the following relations: t e 1 s + t e 1 d = 2 t L + 2 α t e 2 s + t e 1 d = 4 t L + 2 α t e 2 s + t e 2 d = 6 t L + 2 α