A. This class includes methods and apparatus (a) for analyzinglight to measure or test its characteristics, such as intensity, colorand polarization; (b) for determiningthe optical or nonoptical properties of materials or articles bynoting, as by inspection, measurement, or testthe effect produced by the materials or articles on light associatedtherewith; and (c) for measuring the dimensionsof structures or the spatial relationships such as distances orangle bearings of spaced points by comparison of the respectiveproperties (usually direction or spatial position) ofthe light from these points or by comparison of the properties ofthese lights with some scale or standard. The light analyzingincludes or is for spectroscopy, interference, polarization, beamdirection or pattern, focal position of a light source, shadeor color, and photometers. The material or articleproperties determined are or involve crystal or gem examination, materialstrain analysis, blood analysis, optical pyrometers, eggcandling, cutting blade sharpness, oil testing, documentverification, flatness, lens or reflector testing, refractiontesting, monitoring moving webs or fabrics, lighttransmission or absorption, light reflection, inspectionfor flaws or imperfections in materials, and thread counting.
The dimensioning and spatial relationship determination includestriangulation by a light beam, contour plotting, rangeor height finders, motion stopping, velocity or velocity/heightmeasuring, sighting where the optical element or reticlemoves with the sighted object, particle size determination, particlelight scattering, electrophoresis, angle measuringor axial alignment, mensuration or configuration comparison, alignmentin a lateral direction, and fiducial instruments.
B. Included also are apparatus and methods to facilitate theviewing of structure as for flaws and imperfections. Thestructure is usually optically significant such as transparent sheetsor bottles or semi-transparent cloth; or the structureis inaccessible as a bore requiring a bore scope. Includedalso are methods and structure for preparing the sample for an opticaltest, and optical test standards.
C. Included also are apparatus and methods involvinga plurality of measurements or tests each within the scope of thisclass; and also included are a measurement or test withinthe scope of this class together with a measurement or test or otherart structure provided, per se, elsewhere, butwhere no provision for the combination is made elsewhere.