The magnet demagnetization packing 】
Call demagnetization, magnetic did not disappear, only through the magnet magnetic field distribution of the permeability change.
Degaussing packaging in general is to use iron isolation, six surface is fixed inside the box, then use pearl cotton bag, then use carton packing, this for some magnetic weaker magnets, can through the airline's security.
On the market to sell some of the magnetic separation materials will also be able to have better demagnetizing effect, the powerful magnet assembly from the start, reduced the powerful magnet magnetic, to make a strong magnet through the airline security, take a plane.
The principle of magnetic separation is shielding the magnetic field, steady magnetic field or more refers to the low frequency magnetic field, mainly by the magnetic field circuit, if the box is made of high permeability data, would would have to wear out of box & quot;
Lines of magnetic force & quot;
Converge at data form a closed box body, thereby leakage magnetic field lines outside the box is greatly reduced.
For the realization of the magnetic field shielding, the higher the permeability data, the better;
The same data, the thicker the better;
The same material and thickness, the more layers, the better.
Other, magnets shall be placed in the shielding box central, lest one side of the field lines more, have gathered to leak out even more.
If want to block the high frequency magnetic field, a method is to use: use conductive materials such as metal, with high frequency magnetic field on the form of alternating electric eddy current, form opposite to offset the original magnetic field of magnetic field, the essence is the superposition of two magnetic field, the shielding external destructive, inside the shield of the new magnetic circuit.
Information about the second point, magnetized.
Magnetic material in magnetic field, is always to be magnetized, but in addition to the hard magnetic material, once the removal of the external magnetic field, the magnetic promptly followed to eliminate.
So if shielding materials made from hard magnetic materials, magnetic fields, and formed a new independent function will be affected, because of this is shielding can only use soft magnetic materials.
If you ask, since the soft magnetic materials will be magnetized in a magnetic field, how end shield?
This is due to be magnetization of soft magnetic materials, as well as for the new magnetic field intensity, depends on outside the original field intensity change, and then according to the above principle of high frequency magnetic field shielding, destructive and implementation & quot;
Shielding & quot;
Lines of magnetic force & quot;
Is the image that is a substance in the stack.
In a vacuum magnetic shielding, because the air is a paramagnetic material, permeability slightly larger than a vacuum, so in theory the vacuum magnetic shielding effect is better in the air, but little on the project.
Due to the material of paramagnetic and diamagnetic material (ratio of relative permeability of a vacuum
Also is the relative permeability)
, close to 1, but at most a few parts per thousand different;
And permeability data (
The relative permeability at hundreds of thousands, hundreds of thousands, even.
Is reason, on the engineering of the material of paramagnetic and diamagnetic material into consideration.
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