(under the class definition) Subject matter involving preparation or conditioning of an article or substance or a sample of the article or substance to facilitate or enable the later optical test and in combination with such an optical test, wherein the preparation or conditioning is significant and is not provided for in any other class.
SEE OR SEARCH CLASS
73, Measuring and Testing, particularly
23, for gas analysis and 53.01+ for the testing of liquid or liquid suspension of solids, and subclass 421 for samplers and tollers for gases and liquids including closed conduit type samplers.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,
50+, for analyticalcontrol apparatus and apparatus which use sorbents or in which chemical reactions are produced.
436, Chemistry: Analytical and Immunological Testing, 1+, for processes involving analytical control and use of sorbents or chemical reactions.
