A Horizontal Magnetic Field Measurement Scheme Based on Helmholtz Coil Combined with Small Magnetic Needle and Projection Amplification Method

A magnetic field measurement device was designed and built based on Helmholtz coils, combined with small magnetic needles and Projection amplification method. The device utilizes the geomagnetic field and two-dimensional Helmholtz coil magnetic field, combined with a small magnetic needle to indicate the direction of the magnetic field, to measure the horizontal two-dimensional component of the three-dimensional magnetic field at any point in space. During the process, use the projection magnification method to enlarge the projection for reading and reduce errors. The comparative analysis between the experimental measurement numerical calculation results obtained and the theoretical values shows that the errors are all less than 3.0%. The plan also designed devices with different accuracy and measurement ranges under different setting conditions to meet the measurement needs of magnetic fields of different intensities.