Abstract: A permanent or variable magnetic field circulation sensor including apparatus for magnetic excitation further including at least one elongated excitation coil extending around an elongated supple magnetic core and including a supple magnetic material with low relative magnetic permeability having a supple or flexible matrix in which magnetic particles are dispersed, an excitation current generation unit coupled to the excitation coil to generate an excitation magnetic field in the core over substantially the entire length of the coil, apparatus for measurement including: at least one magnetic measuring transducer magnetically coupled to the apparatus for magnetic excitation, a measuring unit connected to the magnetic measuring transducer and suitable for providing a measurement of magnetic field circulation in the core.

Abstract: A magnetic core for a magnetic field sensor is made from a material having a solid matrix in which are dispersed superparamagnetic particles, the solid matrix being chosen so as not to perturb the magnetic properties of the superparamagnetic particles, and so that the superparamagnetic particles represent a percentage P of the total volume of the core chosen to be greater than 2.5% or chosen in the span defined by the relation L 10%?P?L?1% where L corresponds to a threshold L beyond which the core loses the superparamagnetic properties. A magnetic field sensor that includes the magnetic core and an electronic circuit for measuring a magnetic field induced in the magnetic core.

Abstract: A device for measuring the position of a mobile part (4), includes: at least one magnetic node (10) capable of modulating the amplitude of an excitation magnetic field according to the amplitude of a magnetic field to be measured, the magnetic node having a magnetic cycle for magnetic induction that depends on the hysteresis-free magnetic field in an operation range [Hmin; Hmax], and in which the magnetic cycle of the magnetic node (10) is characterised in that the absolute value of the third derivative of the magnetic induction relative to the magnetic field is maximal for a zero magnetic field.

Abstract: The invention relates to a magnetic field sensor comprising at least one magnetic core (10) in which the magnetic cycle of the magnetic core is characterised in that the absolute value of the third derivative of the magnetic flux density in relation to the magnetic field is maximum for a zero magnetic field.