The Vibrating Sample Magnetometer (VSM) is used to measure the magnetic properties of solids and liquids. The magnetometer measures magnetic moment as a function of an applied magnetic field. A unique feature of this system the ability to measure (inverse) magnetostriction using a special sample holder that strains the sample during measurement. these systems were developed using modified audio speakers, though this approach was dropped due to the interference through the produced in-phase magnetic noise, as the magnetic flux through a nearby pickup coil varies sinusoidally. The induced voltage in the pickup coil is proportional to the sample’s magnetic moment , but does not depend on the strength of the applied magnetic field . In a typical setup, the induced voltage is measured with a lock-in amplifier using the piezoelectric signal as a frequency reference. It is also possible to record the hysteresis curve of a material by sweeping the magnetic field.