Special requirements for associated equipments used in an electrical fast transient/burst immunity test

Three kinds of electrical fast transient (EFT) pulse wave forms are defined with three sets of formulas. Based on the formulas, the spectral distribution of EFT signals are deduced by using the method Fourier series expansion. An experiment is designed to verify the deduction and measure the electric field near equipment under EFT test. The results show that the electric field is strong at low frequency band (less than 200MHz, especially several hundred kHz). According to near field radiation theory, the magnetic field may be stronger. So, associated equipments (AE) used in an EFT test should be able to operate normally under such interference.