The results of several round-robin exercises on electrochemical impedance spectroscopy are published now:
50 free copies are available for download here: https://www.tandfonline.com/eprint/3JDCUX8SPM27FUXIXS7H/full?target=10.1080/1478422X.2020.1850070. The accepted manuscript will be published “green open access” after the embargo period has ended (Nov 26, 2021) here: https://www.dora.lib4ri.ch/psi/islandora/object/psi:35138