| A Fluxgate magnetometer (FGM) is a vector device for measuring the components of magnetic field directly by utilizing the non-linear magnetic characteristics of ferromagnetic core material in its sensing element. It is widely used in domains of science research, industrial manufacture, daily life and et al. Therefore, it is significant to develop fluxgate magnetometers with high precision, good stability, high resolution and low power consumption.Based on the review of the development of the fluxgate magnetometers, the basic working principle of the FGM has been discussed in details. The influence of structural parameters on the sensitivity of the FGM has been analyzed. The mathematical model of the ring-core type sensor is established, by which the second harmonic output voltage and its sensitivity is derived and the analysis of the sensitivity versus the structural parameters is done. According to the closed-loop system requirements, the design theory of spherical feedback coils producing a homogeneous magnetic field has been investigated and the relationship between homogeneity and design parameters such as coil grooves and coil spacing is analyzed. Results of the analysis indicate that a large volume homogenous magnetic field generated by spherical coils in a small geometric scale is obtained. In order to achieve accurate feedback for improving system performance, it is necessary to study the temperature properties of the magnetic core. Therefore, the dynamic hysteresis loop and temperature response are studied by using oscilloscope. Finally, the measuring errors of the magnetometers caused by non-orthonormality, different sensitivities between three axes and zero shifts are carefully caculated. Error compensation coefficients are given by using the least-squares method and the error correction can be realized.To make a study of the performance of the sensor is prepared for the design of fluxgate magnetometer. Moreover, its futher optimization is under consideration.
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