Experimental Data for Locating VSM Pickup Coils and Minimizing the Image Effect

From measurements of the magnetic field produced in the air gap of an electromagnet by a small permanent magnet sample, we can predict the relative sensitivity of a vibrating-sample magnetometer (VSM) for any practical location of the pickup coils. By repeating the measurements with the pole pieces removed, we can simulate the case of complete magnetic saturation (permeability μ = 1) of the pole pieces, and thus predict the relative magnitude of the image effect for any coil location. Under some conditions, a coil position can be chosen that eliminates the image effect.