Gaussmeters are used to measure the magnetic field density at the surface of the magnet. This is referred to as the surface field and is measured in gauss (or tesla).  Pull Force Testers are used to test the holding force of a magnet that is in contact with a flat steel plate. Pull forces are measured in pounds.  Fluxmeters and Helmholtz coils are used to measure the magnetic moment.  Learn more in our article about Measuring Magnets.