IEC 61557-5:20 19 RLV包含官方IEC国际标准及其红线版本。Redline版本不是官方文档，它只有英文版本，为您提供了一种快速简单的方法来比较IEC官方标准与其以前版本之间的所有变化。 IEC 61557-5:20 19规定了适用于使用交流电压测量对地电阻的测量设备的要求。IEC 61557-5:20 19取消并取代了2007年发布的第二版。本版构成技术修订版。与上一版相比，此版本包括以下重大技术变更: a)修改第3条中的定义和符号； b)第4条中的子条款经过重组并与该系列的其他部分保持一致；c)降低电压25 V RMS或35 V峰值的限值从4.5移除； d)增加了对夹具的要求； e)第5条中增加的对地额定电压和测量类别的标记； f)第5条中增加的关于不存在危险电压的警告； g)将第6条中的术语“操作不确定性百分比”替换为“操作不确定性”； h)表1中校正的不确定度方程； i)增加了关于带环夹的测试测量的新附录A。

IEC 61557-5:2019 RLV contains both the official IEC International Standard and its Redline version. The Redline version is not an official document, it is available in English only and provides you with a quick and easy way to compare all the changes between the official IEC Standard and its previous edition.

IEC 61557-5:2019 specifies the requirements applicable to measuring equipment for measuring the resistance to earth using an AC voltage. IEC 61557-5:2019 cancels and replaces the second edition published in 2007. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) definitions and symbols in Clause 3 modified;
b) subclauses in Clause 4 restructured and aligned with other parts of the series;
c) limits for reduced voltages 25 V RMS or 35 V peak removed from 4.5;
d) requirements for clamps added;
e) marking for rated voltages to earth and measurement category added to Clause 5;
f) warning about absence of hazardous voltage added in Clause 5;
g) the term "percentage operating uncertainty" replaced by "operating uncertainty" in Clause 6;
h) equation for uncertainty corrected in Table 1;
i) new Annex A on test measurements with loop clamps added.