 The most common way to measure magnetic torque is to mount the sample on a cantilever and measure the displacement via capacitance measurement between the cantilever and nearby fixed object, or by measuring the piezoelectricity of the cantilever, or by optical interferometry off the surface of the cantilever.Faraday force magnetometry uses the fact that a spatial magnetic field gradient produces force that acts on a magnetized object, F=(M⋅∇)B.In Faraday Force Magnetometry the force on the sample can be measured by a scale (hanging the sample from a sensitive balance), or by detecting the displacement against a spring.