EMS Panel (Low Frequency & Static Magnetic Field Countermeasures)(Tap to display menu)
EMC Countermeasure Products
Performance test data
The electromagnetic shielding graph above shows the measurement of "shielding magnetic field strength" at frequencies between 30Hz and 300KHz. EMSpanel shields low-frequency magnetic fields generated by AC currents and induction cookers, which conventional coating materials have little or no shielding performance against. The graph below shows the electric field shielding data measured by the KEC method for high-frequency electromagnetic wave noise.
Theoretical support
1. Theoretical formula for electromagnetic shielding effectiveness
The larger S, the greater the electromagnetic shielding effect. Therefore, it is necessary to select a material with a large δ for the electromagnetic shielding material. For the EMS pad, a high-permeability magnetic material sheet (120 μm thick) was used.
2. Improved electromagnetic shielding rate through multi-layering of materials
The theoretical formula for the electromagnetic shielding effect S when the material is multi-layered is shown below.
The larger S is, the higher the electromagnetic shielding effect is. Electromagnetic shielding performance is improved by laminating electromagnetic shielding materials. EMSpanel is made up of a five-layer structure of aluminum foil and high-permeability magnetic material sheets.
3. Shielding magnetic field strength measurement test
The shielding magnetic field strength is measured using the following method [Figure 2]. A tracking pulse is transmitted from a transmitting loop antenna and received by a receiving loop antenna separated by the material under test, and the shielding strength is measured.
▲ 図2 遮蔽磁界強度測定examination方法
The results of the shielding magnetic field strength measurement test for EMSpanel are shown in Figure 3. This sheet is made up of a five-layer structure of aluminum foil and high-permeability magnetic material sheets, and despite its thickness of 0.7 mm, a shielding magnetic field strength measurement test at the material value confirmed a maximum shielding rate of approximately 60 dB (99.9%) in low-frequency electromagnetic fields from 100 Hz to 300 kHz. It has been confirmed that the low-frequency electromagnetic field emitted by induction cookers has the strongest energy in the 20 kHz to 30 kHz range, and the shielding rate in this vicinity was confirmed to be 60 dB (99.9%).
▲Figure 3. Shielding performance measurement data
（※Note: This is a logarithmic scale of 10 squared, so it is not uniform.）
References: Latest Electromagnetic Wave Absorption and Shielding, Nikkei Technical Books