Miniaturized Rotational Probe For Magnetic Field Mapping

Abstract

This thesis introduces a miniaturized rotational probe for magnetic field mapping. Different from conventional approaches that rely on hall elements for measuring magnetic fields, this device utilizes the principle of electromagnetic induction. Leveraging the characteristics of printed circuit board (PCB) for high integration of electronic components, tiny and precise coils are integrated onto PCB with capability of high-speed rotation. To ensure device stability and integration, the adjustable speed power system and signal transmission system of the rotating coil are combined using 3D modeling and printed brackets. The components fixed on this bracket are detachable, providing convenience for possible adjustments and component substitution. The device is easy to operate and provides fast measurements. It allows for quick adjustment and determination of the position of the points under test through the position coordinates on the baseboard and the magnet positioning bracket. In the tests, measurements were conducted using oscilloscope at different placement inside an NMR permanent magnet and different speeds of the coils. Calibration point was selected based on the measurements, and the average difference was 3.6% compared to the results obtained using the Hall probe. The magnetic field distribution in nine different positions inside the magnet was plotted. This rotating probe is highly suitable for measuring the specific distribution of small-scale magnetic fields, making it applicable in scientific research, industrial monitoring, medical diagnostics, and other fields.