A METHOD OF DATA ACQUISITION AND SYSTEM CONTROL THROUGH TIME SHARING OF MIXED INPUTS

Abstract : In recent years, the demand for more versatile, remotely readable measuring devices has caused us to progress, for example, from the simple mechanical extensometer to the electrical resistance wire gage and from the purely mechanical dial gage to the variable differential transformer pick up. Instruments of this type transducers - have a common property, viz., they transform some particular physical behaviour into an electrical signal or change thereof. Virtually all quantities with which engineers deal can be so transduced, and the outputs from the devices and varied transducers used cover the whole spectrum of electrical signals- dc, ac, and frequency. Thus an inexpensive recording system which can accept any or all of these types of input, sample the various channels in turn and present the time dependent data as an accurate numerical quantity is clearly desirable. The purpose of this thesis is to report the progress made in the design of such an instrument.