Measurements on and with nonlinear systems: Problems and approaches
Abstract
Whenever the relationship between two qualities is anything other than a straight line, time variations of one quality at one set of frequencies will result in variations of the other quantity at a different set of frequencies. Nonlinear systems are frequencycreative. This is an inherent property of nonlinear systems, and can, in fact, be used as a check on system linearity. This property of linear systems may be desired when new frequencies are to be created, such as in frequency multiplication, division or in modulators of all kinds. This property is undesired and can create havoc in those measuring systems in which any of the following criteria are to be met: (1) Frequencycontent reproduction or spectralcontent reproduction, for subsequent analysis as signatures, thumbprints, patterns, etc.; (2) Waveshape reproduction with subsequent analysis of patterns; (3) Peaktopeak reproduction of wave shapes, as in calibration signals with square waves of injected resistance changes (shunt calibration); (4) Integration of signals; and (5) Differentiation of signals.
 Publication:

Range Commanders Council Twelfth Transducer Workshop
 Pub Date:
 1983
 Bibcode:
 1983rcc..work....2S
 Keywords:

 Frequencies;
 Frequency Measurement;
 Linearity;
 Nonlinear Systems;
 Gas Turbines;
 Harmonic Generators;
 Mathematical Models;
 Sine Waves;
 Steady State;
 Time;
 Transducers;
 Instrumentation and Photography