(under subclass 40) Subject matter wherein there is included generally means to support a light reflective or transmissive standard or a light emissive standard formed as part of the test apparatus whereby the standard is compared simultaneously side by side with the specimen either for equality of shade of color and light intensity or for intensity of light alone.
SEE OR SEARCH THIS CLASS, SUBCLASS:
46, for light standards, per se.
243.1+, for optical standards generally.
403, for the merging of colors or patterns generally.
413, for colorimeters generally of the Duboscq type.
414+, for colorimeters testing colored liquids generally which utilize a solid or liquid transmissive standard, and including standard optical wedges, Nessler tubes and micro-colorimeters. 420, for a colored light source, per se, which may be utilized as standards.
421+, for reflective colored standards which include discs, drums, tapes or plates.
425, for the determination of color generally by light intensity comparison.
SEE OR SEARCH CLASS
359, Optics: Systems (Including Communication) and Elements,
831+, for prisms which may be used as standards.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, appropriate subclasses, especially
50+, for laboratory devices or apparatus of quantitative or qualitative analysis involving either a physical or a
