DIFF Subgroup Additional Only
G01J 2001/4446 Full Title
Photometry, e.g. photographic exposure meter (spectrophotometry G01J3/00; specially adapted for radiation pyrometry G01J5/00 ) > using electric radiation detectors (optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10) > Electric circuits
Of 6 combined children, 0 exist in both systems.
6 codes are CPC-only extensions.
Note: 6 CPC extensions are marked as secondary classification only.