The source of disturbance covered by this section is basically an electromagnetic field, coming from intended RF transmitters, that may act on the whole length of cables connected to installed equipment. The dimensions of the disturbed equipment, mostly a sub part of a larger system, are assumed to be small compared with the wavelengths involved. The incoming and outgoing leads: e.g. mains, communication lines, interface cables, behave as passive receiving antenna networks because they can be several wavelengths long.

Between those cable networks, the susceptible equipment is exposed to currents flowing "through" the equipment. Cable systems connected to equipment are assumed to be in resonant mode and as such are represented by coupling and decoupling devices having a common mode impedance of 150 ohms with respect to a ground reference plane.

This test method subjects the EUT to a source of disturbance comprised of electric and magnetic fields, simulating those coming from intentional RF transmitters. These disturbing fields (E & H) are approximated by the electric and magnetic near fields resulting from the voltages and currents of the test setup.