Subclass Subgroup Patent
G01N 21/1717 12169170
  21/31 12169171
  21/3518 12169172
  21/3577 12169173
  21/39 12169174
  21/6458 12169175
  21/77 12169176
  21/8803 12169177
  21/9501 12169178
  21/9503 12169179
  21/952 12169180