(under subclass 409) Subject matter including an unknown solution and one or more standards (which may be a transmissive liquid or solid or a reflective standard or any combination thereof) for the simultaneous comparison of the unknown solution with the standard or standards for similar color or slight differences in the same color which color standard or standards are correlated to ionic conditions existing in the solution examined.
(1) Note. Included in this group are apparatus which involves the finding of the pH value of solutions in terms of hydroxyl or hydrogen ion concentration, and titration apparatus in which no reagent is recited in the claims; and also included are other tests which involve the correlation
of the tint or shade of a color with respect to the color of the standard solution in which the ion content is known.
(2) Note. The disclosure of the tests recited in (1) Note above is sufficient for placement in this subclass.
(3) Note. Included are optical tests to determine the concentration of solute in solvents.
SEE OR SEARCH THIS CLASS, SUBCLASS:
414, for filters which include solid and liquid filters and standards of the transmissive type where no ionic analysis is involved and no concentration of the solute and solvent is involved.
416+, for transmissive filters involved in a comparison test of gases or solid material. SEE OR SEARCH CLASS
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,
50+, for chemical apparatus having means for performing color tests involving pH and titrations which claim the reagents, including the indicators, which chemically react in the tests.
436, Chemistry: Analytical and Immunological Testing,
1+, for chemical test processes which include color tests involving pH and titrations which claim the reagents, including the indicators, which chemically react in these tests.
