This standard BS EN 61337-1:2004 Filters using waveguide type dielectric resonators is classified in these ICS categories:
31.140 Piezoelectric devices
IEC 61337-1:2004 applies to filters using waveguide type dielectric resonators of assessed quality using either capability approval or qualification approval procedures. It also lists the test and measurement procedures which may be selected for use in detail specifications for such filters.