IEC 62631-3-2:2015 covers methods of test for the determination of surface resistance and surface resistivity of electrical insulation materials by applying DC voltage. This first edition cancels and replaces the second edition of IEC 60093, published in 1980, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the second edition of IEC 60093: a) IEC 60093 has been completely revised, both editorially and technically, and incorporated into the new IEC 62631 series; b) test methods have been updated to current day state of the art; c) volume and surface resistance and resistivity are now separated into IEC 62631-3-1 and IEC 62631-3-2, respectively.