When the frequency of the factors affecting the shielding data effect of the electromagnetic shielding machine room is high, the absorption loss is the main shielding mechanism, which has little to do with whether the radiation source is an electric field or a magnetic field. When the frequency is low, the absorption loss is very small, and the reflection loss is the main mechanism of shielding efficiency, so the reflection loss should be increased as much as possible.
Electric field wave is easy to be shielded, followed by plane wave, and magnetic field wave is difficult to be shielded, especially low-frequency magnetic field (below 1kHz). For low-frequency magnetic fields, high permeability data shall be used for shielding. There are several conditions that will affect the effect of shielding data, and even the combination of high conductivity data and high conductivity data.
The better the conductivity and magnetic conductivity data are, the higher the shielding efficiency is. However, these two aspects cannot be considered in the practical application of metal data. For example, copper has good conductivity but poor magnetic conductivity; Iron has good magnetic conductivity but poor conductivity. On the basis of detailed shielding, what information should be used mainly depends on the reflection loss or absorption loss to decide whether to focus on conductivity or magnetic conductivity.
The reflection loss is related to the distance between the shielding layer and the radiation source. For the electric field radiation source, the closer the distance, the greater the reflection loss; For the magnetic radiation source, the closer the distance is, the smaller the reflection loss is. Correctly identifying the nature of the radiation source and determining that the radiation source should be close to the shielding layer is an important part of the structural design, and the shielding layer is still the main body of the shielding layer.