Portable precision electronic caliper

A portable electronic precision caliper, comprising:

• a shaft fitted with a magnetized scale having a period of magnetization λ,
• a slide that is displaceable longitudinally along said shaft, the slide and the shaft each having a jaw,
• an electronic circuit mounted on said slide and being powered with an internal power source, said electronic circuit comprising a single sensor,
• said sensor comprising an array of n magnetoresistive electrodes disposed opposite said scale so that values of resistances of the magnetoresistive electrodes are a function of their longitudinal position along the scale, n being greater than two,
• said electronic circuit being able to determine, from the values of resistance of the magnetoresistive electrodes, information depending on a gap between said jaws and to display this information on said electronic display,
• said array of magnetoresistive electrodes consisting of a plurality of sets of magnetoresistive electrodes each comprising at least 8 electrodes connected in series, a thickness of the nagnetoresistive electrodes being less than 100 nm, a length of said magnetoresistive electrodes being between 0.1 and 10 millimeters and a width of said magnetoresistive electrodes being less than 40 μm, so that a resulting resistance of each set of magnetoresistive electrodes is greater than 10 kΩ, so that said caliper can be powered with an internal power source.