DIN EN 61788-12:2014-04

This part of DIN EN 61788 describes a test method for determining the copper to non-copper volume ratio of Cu/Nb₃Sn wires. The test method given here is applicable to Nb3Sn composite superconducting wires with a cross-sectional area of 0,1 mm² to 3,0 mm² and a copper to non-copper volume ratio of 0,1 or more. The method does not make any reference to the filament diameter; however, it is not applicable to those superconducting wires with their filament, Sn, CuSn alloy, barrier material and other non-copper portions dispersed in the copper matrix or those with the stabilizer dispersed. Furthermore, the copper to non-copper volume ratio can be determined on specimens before or after the Nb₃Sn formation heat treatment process. The Cu/Nb₃Sn wire has a monolithic structure with a round or rectangular cross-section. Though uncertainty increases, this method may be applicable to the measurement of the copper to non-copper volume ratio of the Cu/Nb₃Sn wires whose cross-section and copper to non-copper volume ratio fall outside the specified ranges. This test method may be applied to other composite superconducting wires after some appropriate modifications. The responsible body is DKE/K 184 "Supraleiter" ("Superconductors") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.