Oscillation of interfacial properties in liquid systems: assessment of harmonic distortion

The total harmonic distortion (THD) parameter is applied to oscillation experiments involving interfacial phases. The THD-value appears a suitable index which can be used for a quantitative estimation of the goodness of the linearity hypothesis, as assumed in the theoretical interpretation of the interfacial excitation-response behaviour. Example experimental results grant a validity domain of the linearity hypothesis and an amplitude-range tolerability for the external forcing excitation.