EMI (Electro-Magnetic Interference) comes in different forms, frequencies, and levels. Electronic equipment has different categories for both emissions and susceptibility. Under normal circumstances elimination is not possible so reduction to acceptable levels is what can be reasonably achieved. Coupling factors, rise time, emissions and susceptibility are phrases that must be understood with confidence. It is less “Black Art” than the urban legends lead you to believe. It’s well founded in principal and practice.