DIFF Subgroup
G01R 31/1227 Full Title
Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere ( testing line transmission systems H04B3/46; testing or measuring semiconductors or solid state devices during manufacture ) > Testing dielectric strength or breakdown voltage
Of 4 combined children, 0 exist in both systems.
4 codes are CPC-only extensions.