Detecting a magnetic field is simple, but measuring its intensity is more complex! This magnetometer project uses the integration method to measure intensities from a few Gauss to several Teslas, with affordable, self-made sensors.

Looking for a means to measure the magnetic field of single and arrangements of NbFeB magnets, I remembered a kind of “archaic” method, i.e., the integration of the voltage pulse that is induced when a probe coil is placed into the unknown field. In the old days, such measurements were performed by “ballistic” or “creep” galvanometers that reached the (astonishingly high) sensitivity of a few μVs. For further information, you can consult Chapters VI to IX of the ancient — yet very valuable — text here. So, my challenge was to try to realize such a measurement using more modern electronic means, namely an operational amplifier-based integrator.

For the hobbyist, the advantage of this method is the possibility to home-make the required sensors (sensor coi...