Evaluation of Measurement Uncertainty of Shielding Effectiveness for Electromagnetic Shielding Films

The shielding effectiveness(SE) measurement uncertainty for electromagnetic shielding films is evaluated and analyzed, using flanged coaxial tester in the frequency range of 30 MHz - 8 GHz. Mathematical model is established , considering the influence sources of measurement uncertainty, including the measurement repeatability , maximum permissible errors of measurement instruments, mismatch errors caused by measurement instruments and flanged coaxial tester. The evaluation results show that expanded measurement uncertainty of shielding effectiveness for electromagnetic shielding films is 1.2 dB, with a coverage factor k equals to 2, which meets the measurement requirement of standard tester.