It is used for testing the electromagnetic shielding effectiveness of electromagnetic shielding materials, such as textiles, plastic cloth, metal sheet, non-conductive material surface coating or coating, metal mesh, conductive film, conductive glass and conductive dielectric plate.
GB/T 23326 Electromagnetic shielding of stainless steel fiber and cotton polyester blended fabric
GB/T 25471 Measurement method of shielding effectiveness of electromagnetic shielding coatings
SJ 20524 Measurement method of shielding effectiveness of materials ASTM 4935
Principle of instrument:
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Structure diagram
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1. Shielding effectiveness（SE）
The logarithm of the ratio of the power or voltage received by the shielding material to the unshielded material at the same excitation level. The formula is as follows:
VO—Receiving voltage of unshielded material
VI—Receiving voltage with shielded material
PO—Receiving power of unshielded material
PI—Receiving power with shielded material
2. Test process
According to the standard GBT25471-2010, the test and the dampness are taken. First, the reference sample is used to measure at multiple frequency points, and the recorded value is PO (or VO) at each frequency. Then the measurement sample is measured at multiple frequency points, and the recorded value is PI (or VI) at each frequency. The shielding effectiveness is calculated with the above formula.
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