Magnetic field sensing using a fluxgate magnetometer

Basic principles

How does a fluxgate work?

A fluxgate magnetometer works by exploiting the nonlinear magnetic response of a ferromagnetic core to detect an external magnetic field. It detects changes in magnetic permeability due to the presence of an external field, typically producing a signal at 2nd harmonic of the excitation frequency.

In a fluxgate sensor, the core material has very high magnetic permeability $\mu$. This means, the core material can concentrate magnetic fields very well. It reacts strongly to changes in external fields. Its permeability changes nonlinearly as the material saturates, which is crucial for generating detectable signals (like the 2nd harmonic) when there's an external field.

Illustrations of a fluxgate:

Introduction to the fluxgate magenotometer

We plan for a setup....

Modelling and measurements of a permanent magnet

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