CISPR 11 / EN 55011 : What measurement distance for Class A and Class B?

In the new CISPR 11 / EN 55011:2025 standard, the measurement distances for Class A and Class B equipment are defined as follows:

• For small EUTs (see CISPR 11 / EN 55011 : What is a ‘small EUT’?):
  • In a semi-anechoic chamber (SAC): 3 m, 10m or 30 m
  • In an open area test site (OATS): 3m, 10 m or 30 m
  • In a fully anechoic chamber (FAC): 3 m (EUT must be a table-top equipment and must fit within)
• For large EUTs (that does not fit the definition of small EUT):
  • In a semi-anechoic chamber (SAC): 10 m or 30 m
  • In an open area test site (OATS): 10 m or 30 m
  • In a fully anechoic chamber (FAC): Not applicable (since a large equipment is not “table-top”)