DIFF Subgroup
G01J 1/122 Full Title
Photometry, e.g. photographic exposure meter (spectrophotometry G01J3/00; specially adapted for radiation pyrometry G01J5/00 ) > by comparison with reference light or electric value > using wholly visual means (G01J1/20 takes precedence)
Of 1 combined children, 0 exist in both systems.
1 codes are CPC-only extensions.