It’s something [mircemk] demonstrates, with an Arduino-powered magnetic field strength meter that uses a UGN ... Surprisingly such projects are few and far between here at Hackaday, however ...

User [mircemk] presents his “MiliOhm Meter” project which you can build with an Arduino, a handful of common parts from your lab, and a cigar box. It doesn’t get much simpler than this, folks.