Why so many groups?
A major reason for dividing up the work in the IEC is to have certain committees responsible for the different types of EMC publications – basic, generic and product Standards. Some of these committees have broad-ranging horizontal functions while others have more product-oriented (or vertical) responsibilities.
Also, as we have seen, the term EMC is not restricted to the high-frequency ranges but applies to the whole spectrum of EM phenomena. For practical as well as historical reasons, the IEC has divided the spectrum into low-frequency and high-frequency phenomena, setting a line at 9 kHz, which is the lower limit in the scope of CISPR work.
This results largely from the different characteristics of the various phenomena and the specialized experience of experts working on EMC standardization in many technical committees both within the IEC and externally.