Some Dynamometric Applications of an Electronic Integrator-Differentiator

Abstract

One of the authors (J. G.) has devised an electronic integrator-differentiator which can be connected to two recorders which will then record in one operation the classical load-extension curve, the work of stretching, and the slope of the load-extension curve. The recorders give a continuous trace from which at any moment can be read off as ordinates the corresponding work of stretching and the rate of loading or rate of exten sion. The technique can be applied equally well to measurements made by dynamometers on fibers, yarns, rovings, or slivers. Moreover, the integrator-differentiator circuit which is used is also appropriate for many additional uses, since it can be fed by the variable voltage which is produced in many types of apparatus now being widely used in the laboratory. In this way, without any additional work, both the integrated and the differentiated curve can be obtained for whatever function is being measured.-

The authors have employed this circuit for (1) a critical study of the extent to which the constancy of rate of loading or extension is realized in two yarn dynamometers which have been put on the market recently, and (2) for the continuous measurement of the work of stretching and the rate of loading of woul, nylon, Terylene, and other fibers when they are being tested on a dynamometer supposed to give a constant rate of extension.

Quite apart from the advantage of having the integration and the differentiation proceeding instantaneously, this electronic device also allows a careful investigation of the effect of time in various dynamometric studies of fibers, rovings, and yarns.