The design, development and construction of a low cost multi-purpose computer/interface system for on-line experimentation: applications to time averaging of NMR spectra and other chemical instrumentation problems

Abstract

The project goal was the development of a low cost multipurpose microprocessor interfacing system that would be adaptable to a number of commonly encountered chemical instruments (such as NRM, GC, IR, and UV-VIS.) for the purpose of control, data acquisition processing. The Altair Microprocessor with 4K random access memory was constructed from kit form; it functions as the computer portion of the system. The digital to analog and analog to digital signal conversion elements as well as timing, control and other necessary logic functions are incorporated in the electronic interface portion of the system. The computer, interface, principles of time averaging, and the philosophy of interfacing in general, are the subjects of this report. The Perkin Elmer R-24A NMR spectrometer is presently attached to the computer/ interface system so that signal time averaging on low concentration samples may be accomplished. A by-product of this particular system is a library of spectra stored on binary coded paper tape which can be used to generate spectra without having to make up samples. Future applications of the system are also considered in this thesis