TEMPERATURE STABILITY OF SENSITIVITY AND OFFSET IN COIL-LESS FLUXGATE SENSORS

Mattia Butta – Pavel Ripka

   Temperature stability of fluxgate sensors is very important issue, because this kind of sensors has found applications in several field where temperature is not constant. Temperature determines dilatation of the material which can result in mechanical stress to the core. In this paper we compare orthogonal fluxgates in coil-less mode, obtained with bi-phase Copper/Permalloy microwires with and without glass layer between them. We show that a glass layer between Copper and Permalloy strongly decreases the dependence of both offset and sensitivity on the temperature. We explain this by the fact that glass has lower thermal expansion coefficient than copper, therefore it compensates its dilatation which is source of mechanical stress for the Permalloy.

Keywords: orthogonal fluxgate, coil-less fluxgate, temperature stability, offset, sensitivity, characteristic, thermal expansion, permalloy, copper, glass coated microwires

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