IEC TS 61156-1-2:20 23规定了IEC 61156-1:20 02（第2版）中存在且未纳入IEC 61156-1:20 07（第3版）中的对称对/四方电气传输特性和测试方法。详细介绍了特性阻抗测试方法和函数拟合程序、开路/短路方法以及不平衡衰减测量的背景。 它通过对无巴伦测量技术的描述进行了扩展，这是对以前技术报告的修订，并得到了改进并纳入了新版本。完整的文档被转换为技术规范。

IEC TS 61156-1-2:2023 specifies symmetrical pair/quad electrical transmission characteristics and test methods present in IEC 61156-1:2002 (Edition 2) and not carried into IEC 61156-1:2007 (Edition 3). It details characteristic impedance test methods and function fitting procedures, the open/short-circuit method and the background of unbalance attenuation measurement.
It is extended by a description of the balunless measurements technique, which is an amendment to the former technical report and is improved and incorporated into this new edition. The complete document is transferred into a technical specification.