Gouy balance

The Gouy balance is a simple technique for measuring the magnetic susceptibility of metals or metal complexes. This method was invented by the French scientist Louis Georges Gouy (19 February 1854 - 27 January 1926).

A long, cylindrical sample that is to be tested is suspended from a balance, partially entering between the poles of a magnet. The balance measures the apparent change in the mass of the sample as it is repelled or attracted by the region of high magnetic field between the poles. Some commercially available balances have a port at its base for this application.