Multiple time constants measurement: an accuracy-based approach

A considerable number of measurements for material, device and system characterization rely on the analysis of its step response. Sometimes, there is no accepted model for the physical phenomenon, so that not only the values, but also the numbers of time constants are to be determined. A similar case can occur when we must try to choose between different models. This work presents an algorithm to determine the number of the exponential terms in the waveform that can be safely measured given the measurement system accuracy.