The experimental measurement of exponential time constants in the presence of noise

Abstract

There are many experimental situations where the response of a physical system is monitored following the application of a step function in the stimulus. The analog or digitized output signal from such experiments often consists of a noisy transient having the form of an exponential decay. In many cases, a baseline signal is not available. A simple computer method, suitable for on-line use is described for treating the digital data and evaluating the exponential time constant. The accuracy of the baseline restoration technique and of the measurement of exponential time constants in general is estimated using data simulated by the same simple computer program. The applicability of the method to other common experimental situations is discussed.