*2.1.1 Detect all EMI sources on the PCB*

Use near-field probes (either E- or H-field). These small hand-held antennas are mainly used in the development and diagnostics of electronic devices, monitoring the radiation of components and blocks directly inside the developed device, for the most accurate search for the source of the interfering signal at the area of interest or for detecting electromagnetic leaks in shields.

Measurements using a near-field probe are not regulated by any standards. It is only a matter of determining the relative degree of interfering radiation in a given place or a given circuit. EMI sources generally include fast-edge digital signals. When the product contains a shielded enclosure, check the area around the joined parts and near the holes.
