This part of IEC 60763 gives methods of test applicable for the material classified in IEC 60763-1. This edition includes the following significant technical changes with respect to the previous edition:The standard has generally been revised editorially and brought into line with IEC 60641-2; The test method for the determination of the internal ply strength has been replaced with an alternative method; and The test method for the determination of the thermal resistance has been enlarged in its scope.