IEC 61788的本部分介绍了测定铜/超导体比大于1的Cu/Nb-Ti复合超导体或铜/超导体比大于0.9且铜合金（Cu-Ni）/超导体比大于0.2的Cu/Cu-Ni/Nb-Ti导线直流临界电流的试验方法，其中Nb-Ti超导细丝的直径大于1微米。附录C中描述了Cu/Cu-Ni/Nb-Ti的变化。Cu-Ni使用了标准的所有主要部分，但附录C中列出的例外情况取代了（在某些情况下与之相反）正文中的一些步骤。 本方法适用于在标准试验条件下，在小于或等于上临界磁场0.7的磁场下，临界电流小于1000 A且n值大于12的超导体。测试期间，将试样浸入已知温度的液氦浴中。 测试导体具有圆形或矩形横截面积小于2 mm2的整体结构。本试验方法中使用的试样几何形状为感应式卷绕试样。本标准中给出了常规试验和其他特定限制所允许的与本试验方法的偏差。 临界电流大于1 000 A或横截面积大于2 mm2的试验导线可使用本方法测量，预计不确定度增加，且自场效应更显著（见附录B）。其他更专业的试样测试几何形状可能更适用于更大的导体测试，为了简单起见，并保持较低的不确定度，本标准中省略了这些测试。 经过适当修改后，本标准中给出的试验方法有望适用于其他超导复合导线。

This part of IEC 61788 covers a test method for the determination of the d.c. critical current of either Cu/Nb-Ti composite superconductors that have a copper/superconductor ratio larger than 1 or Cu/Cu-Ni/Nb-Ti wires that have a copper/superconductor ratio larger than 0,9 and a copper alloy (Cu-Ni)/superconductor ratio larger than 0,2, where the diameter of Nb-Ti superconducting filaments is larger than 1 micrometre. The changes for the Cu/Cu-Ni/Nb-Ti are described in Annex C. The Cu-Ni uses all of the main part of the standard with the exceptions listed in Annex C that replace (and in some cases are counter to) some of the steps inthe main text. This method is intended for use with superconductors that have critical currents less than 1 000 A and n-values larger than 12, under standard test conditions and at magnetic fields less than or equal to 0,7 of the upper critical magnetic field. The test specimen is immersed in a liquid helium bath at a known temperature during testing. The test conductor has a monolithic structure with a round or rectangular cross-sectional area that is less than 2 mm2. The specimen geometry used in this test method is an inductively coiled specimen. Deviations from this test method that are allowed for routine tests and other specific restrictions are given in this standard. Test conductors with critical currents above 1 000 A or cross-sectional areas greater than 2 mm2 could be measured with the present method with an anticipated increase in uncertainty and a more significant self-field effect (see Annex B). Other, more specialized, specimen test geometries may be more appropriate for larger conductor testing which have been omitted from this present standard for simplicity and to retain a lower uncertainty. The test method given in this standard is expected to apply to other superconducting composite wires after some appropriate modifications.