DIFFERENTIAL SENSOR OF PERMANENT MAGNETIC FIELD Russian patent published in 2014 - IPC G01R33/02 

FIELD: measurement equipment.

SUBSTANCE: sensor comprises a capacitor, the dielectric of which is a magnetostriction-piezoelectric composite placed between coils of Helmholtz coils, which develop the specified alternating magnetic field. When the sensor is placed into a metered permanent magnetic field, mechanical stresses occur in the magnetostriction phase of composite, and they are transmitted into the piezoelectric phase, as a result of which on capacitor plates there is a difference of potentials, which represents a sum of two signals - with standard frequency, the value of which is proportionate to the product of intensities of the permanent and alternating magnetic fields, and with doubled frequency, the value of which is proportionate to the square of intensity of the alternating magnetic field, and they measure the difference of adjacent amplitudes of the output harmonic signal, which is equal to the product of intensity of the permanent magnetic field by the value, which characterises sensitivity of the structure.

EFFECT: use of the proposed sensor makes it possible to increase sensitivity of measurements and to improve noise immunity during measurement.

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