What is a magnetic field ?
A magnetic field is the physical phenomenon produced by electric charges in movement. Various sources of magnetic fields exist such as the Earth, a motor, a transfer or a simple magnet. Magnetic fields can be measured by using Gaussmeters, magnometers or coils linked to an oscilloscope. Magnetic fields are involved in many electro-mechanical applications and can be, in somes cases, a real problem by interfering with other equipment and being very disruptive. With many years of experience in magnetic shielding, Soudupin will provide you the most appropriate solution to your problem, for magnetic fields ranging in intensity from few nanoTeslas to several hundred of Gauss.
What is a magnetic shielding ?
Magnetic shielding aims to reduce the magnetic field in a space by “attracting” the field with magnetic materials. We commonly talk about magnetic shielding when we want to attenuate static or low frequency (>1kHz) magnetic fields, this is the core of our business.
How does it work ?
Our magnetic shields are made with magnetic-permeable metal alloys called ferromagnetic (Iron, Nickel, or Cobalt based). Such materials are capable to “attract” the magnetic field and to “focus” the lines of magnetic flux along its surface. Magnetic shield attenuation mainly depends on the permeability of the chosen material. The higher is the permeability, the higher will be the attenuation. Permeability of ferromagnetic materials varies non-linearly with the magnetic induction H. In other terms, some materials will be preferred for low magnetic fields, other for high magnetic fields.
Materials : The choice of material depends on the characteristics of the magnetic field : its intensity, frequency but also of the desired attenuation. Mumetal is the most common material because of its high permeability at different intensities of magnetic field.
Shape / Geometry : Usage of spherical, cylindrical or round angles preferred over the usage of sharp edges for best results
Thickness : Shield performance increases with thickness of the material
Layers : Shield performance increases with the number of layers. Spacing between layers will also improve the shield performance
These are the main considerations prior to produce a magnetic shield. Many other considerations must be taken into account during manufacturing, but this is our specialty, so do not hesitate to contact us to solve your problems of magnetic interferences.
Mumetal : Ni80FeMo5, high permeability, the most common material used for magnetic shielding
SuperMumetal : Ni80FeMo5, very high permeability
Cryophy : Ni81FeMo5, high permeability, specifically developed for magnetic shielding working at cryogenic temperature
Supra50 : FeNi48, high permeability and high saturation induction
Supra36 : FeNi36, good permeability, high resistivity
Pure Iron : Good permeability for medium and high magnetic field, high saturation induction
Iron Silicon : FeSi3, good permeability for medium and high magnetic field, high saturation induction