Methods for automating and improving the robustness of linear Kramers–Kronig tests for the purposes of validating immittance spectra

Methods for automating the selection of key parameters for linear Kramers–Kronig tests are described. These methods include not only new methods and improvements to existing methods for suggesting the optimum number of time constants, but also methods for estimating the limits of the solution space. Methods for optimizing the range of time constants and a method for suggesting the representation of the immittance spectrum are also described. These methods are evaluated using both valid and invalid synthetic immittance spectra that present various challenges. Practical considerations regarding the implementation of the linear Kramers–Kronig tests and the various methods, the choice of linear Kramers–Kronig test and data representation to use, and the visualization and interpretation of results are also discussed.