For "little" devices whose dimensions are small, compared to the wavelength, radiated phenomenas are essentially due to the cables. Consequently, it is often sufficient to know the current value in them, to evaluate the radiated emission level.

In the following, indicative values for industrial and domestic environment are given.

For larger devices, and/or to know exactly where the disturbance is located, a simple H-probe can be used, the Moebius probe. The measured voltage U give information on the magnetic field H.