IEC 62561-3:2023 is available as IEC 62561-3:2023 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 62561-3:2023 specifies the requirements and tests for isolating spark gaps (ISGs) for lightning protection systems. ISGs can be used to indirectly bond a lightning protection system to other nearby metalwork where a direct bond is not permissible for functional reasons. This third edition cancels and replaces the second edition, published in 2017. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition.
a) alignment with the latest edition of ISO 22479 relating to humid sulphurous atmosphere treatment;
b) addition of a new normative Annex D for the applicability of previous tests.