DIFF Subgroup
G01N 21/636 Full Title
Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light (G01N3/00 - G01N19/00 take precedence) > Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light > optically excited
Of 2 combined children, 0 exist in both systems.
2 codes are CPC-only extensions.
Note: 2 CPC extensions are marked as secondary classification only.