本标准的目的有三:1）定义可用于测量纵向平衡的测试电路的基本要求。该测试电路将能够产生一致且可重复的测试结果。；2） 定义使用测试电路时要建立的测试条件。标准测试条件对于从合适的电路中获得一致的结果至关重要。；3） 描述操作测试电路时应遵循的标准测试程序。本标准仅在一般情况下规定了测试电路的元件，以在设计测试装置时允许相当大的自由度。因此，排除了只有一组电路元件能够满足标准的可能性。 本标准基于电阻测试电路，尽管纯电阻不是必需的。之所以指定电阻元件，是因为通常认为它们易于复制和平衡。发布本标准的目的是重复和一致的余额。平衡电路用于延伸至兆赫范围的频率，可能需要在高频下测量纵向平衡。本标准中给出的纵向平衡度定义和驾驶测试电路的一般配置适用于所有频率。然而，测试电路阻抗和声带外测量的其他要求超出了本标准的范围。

The purpose of this standard is threefold:1) To define the basic requirements of a test circuit which can be used to measure longitudinal balance. This test circuit will be capable of yielding consistent and repeatable test results.; 2) To define test conditions to be established while using the test circuit. Standard test conditions are considered vital for obtaining consistent results from a suitable circuit.; 3) To describe standard test procedures to be followed when the test circuit is operated. This standard specifies the elements of the test circuit only in general terms to allow considerable freedom when a test set is being designed. It thereby precludes the possibility that only one set of circuit elements will be capable of meeting the standard. This standard is based on a resistive test circuit, although pure resistance is not essential. Resistive elements are specified because they are generally considered easy to duplicate and balance. Repeatable and consistent balance numbers are the object of issuing this standard. Balance circuits are used at frequencies extending well into the megahertz range and there may be a need for measuring longitudinal balance at high frequencies. The definition of degree of longitudinal balance and the general configuration of the driving test circuit given in this standard are applicable at all frequencies. However, the test circuit impedances and other requirements for measurement outside the voice band are beyond the scope of this standard.