On Selection of the Perturbation Amplitude Required to Avoid Nonlinear Effects in Impedance Measurements

Numerical simulations of electrochemical systems were used to explore the influence of large‐amplitude potential perturbations on the measured impedance response. The amplitude of the input potential perturbation used for impedance measurements, normally fixed at a value of 10 mV for all systems, should instead be adjusted for each experimental system. Guidelines are developed for selection of appropriate perturbation amplitudes. A characteristic transition frequency is defined that can be used to tailor a frequency‐dependent input signal to optimize signal‐to‐noise levels while maintaining a linear response.