Research on the electronics unit of digital fluxgate sensor

Traditional analog fluxgate sensors have the shortcoming of being disturbed easily by the external environment. To overcome this shortcoming, a digital fluxgate system based on field programmable gate arrays (FPGAs) is described in this paper. The feasibility and accuracy of the system are verified by comparing with the magnetic field data of the geomagnetic stations in Ming Dynasty Tombs. Further experimental results show that the resolution comes to about 0.2nT with a linear dynamic range of about ±65000nT, which is better than the average level of InT in the domestic. Comparing with the analog circuit design of the fluxgate sensor, the digital electronics unit design in this paper has realized a more accurate and stable fluxgate sensor system with a larger measurement range in the three-axis directions, which fully meets the requirements of the magnetic field surveying.