RAMM: A Robotic, Autonomous Magnetic field Mapper.

Accurate spatial mapping of magnetic fields is crucial for a range of scientific, industrial, and medical magnetic devices. Here, we present RAMM: a Robotic, Autonomous Magnetic field Mapper. RAMM consists of a delta-style 3D robot coupled with a three-axis Hall sensor that is able to measure magnetic fields accurately and at relatively low cost. In addition, RAMM is programmatically controlled via a Python interface, facilitating volumetric measurement of x , y , and z -components of magnetic fields ranging from the millitesla to single-digit Tesla range. We demonstrate the performance of RAMM, via detailed 3D-maps of the magnetic fields of several different sizes and arrangements of permanent magnets, and demonstrate agreement between measured and manufacturer-reported field gradient values. RAMM is easy to build, affordable, and suitable for teaching and research applications.