Traces the development of instruments used in spectrophotometry. Discusses how spectrophotometric measurements are made. Describes the color comparator, the filter photometer, and the spectrophotometer. Outlines the evolution of optical systems, including light sources, the monochromator, the photodetector, double-beam optics, and split-beam…

Provides ideas for using the same port connection of personal computers to interface with laboratory instruments. Contains specific instructions on how to build transducers. Includes plans and diagrams for thermistors and light meters as well as computer programs for displaying instrument readings on monitors. (TW)

Described is the construction of a simple analog-to-digital convertor circuit to interface an Apple II+ microcomputer to a light sensor used in conjunction with a holographic gear inspector. A list of parts, circuit diagram, and a simple BASIC program for the convertor are provided. (CW)