Machine Recycling Discussion and Moderated Newsgroup > Full Machines
> Incomplete Machines
> East
> New
> Vibrating sample magnetometer (vsm)
Vibrating sample magnetometer (vsm)
A fine example, super-clean inside and out. Shows absolutely no wear, and appears new.
A Vibrating Sample Magnetometer, or VSM, is a scientific instrument that measures magnetic properties. A sample is placed inside a uniform magnetic
field to magnetize the sample. The sample is then physically vibrated sinussoidally, through the use of piezoelectronic material. Commercial systems
use linear attentuators of some form and historically the development of these systems was done using modified audio speakers, though this approach
was dropped due to the intereference through the in-phase magnetic noise produced, 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 through the use of a lock-in amplifier using the piezoelectronic signal as its reference
signal. By measuring in the field of an external electromagnet, it is posiible to obtain the hysteresis curve of a material.
VSM Principles: VSM operates on Faraday's Law of Induction, which tells us that a changing magnetic field will produce an electric field. This electric field can be measured and can tell us information about the changing magnetic field. A VSM is used to measure the magnetic behavior of magnetic materials.
