IEC 61557-12:20 18作为IEC 61557-12:20 18 RLV提供，其中包含国际标准及其红线版本，显示了与上一版本相比技术内容的所有变化。IEC 61557-12:20 18规定了电力计量和监控设备(PMD)的要求，用于测量和监控配电系统内的电量以及可选的其他外部信号。这些要求还定义了额定电压高达1 000 V AC或高达1 500 V DC的单相和三相AC或DC系统的性能。这些设备是固定的或便携式的。它们旨在用于室内和/或室外。本文件中定义的电力计量和监控设备（PMD）提供了额外的安全信息，有助于验证安装并提高配电系统的性能。本文档中描述的用于电气参数的功率计量和监控设备(PMD)用于一般工业和商业应用。本文件不涉及功能安全和网络安全方面。本文件不适用于: -符合IEC 62053-21、IEC 62053-22、IEC 62053-23和IEC 62053-24的电力计量设备。然而，本文件中定义的有功和无功能量测量的不确定性源自IEC 62053（所有部分）中定义的不确定性； -IEC 61557-2至IEC 61557-9和IEC 61557-13或IEC 62020中定义的电气参数的测量和监测； -根据IEC 62586的电能质量仪器（PQI）（所有部件）； -IEC 60051涵盖的设备（所有部件）（直接作用模拟电测量？仪器）。IEC 61557-12:20 18取消并取代了2007年发布的第一版。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)PMD-A已被撤回，因为这些设备现在主要由IEC 62586系列标准涵盖。 b)已经创建了三类PMD，并为每个类别列出了最低要求的功能。 c)增加了一个新的附件A，解释了与相关标准和设备相关的不同应用，以及另一个关于功率因数公约的新附件C。

IEC 61557-12:2018 is available as IEC 61557-12:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 61557-12:2018 specifies requirements for power metering and monitoring devices (PMD) that measure and monitor the electrical quantities within electrical distribution systems, and optionally other external signals. These requirements also define the performance in single- and three-phase AC or DC systems having rated voltages up to 1 000 V AC or up to 1 500 V DC. These devices are fixed or portable. They are intended to be used indoors and/or outdoors. Power metering and monitoring devices (PMD), as defined in this document, give additional safety information, which aids the verification of the installation and enhances the performance of the distribution systems. The power metering and monitoring devices (PMD) for electrical parameters described in this document are used for general industrial and commercial applications. This document does not address functional safety and cyber security aspects. This document is not applicable for:
– electricity metering equipment that complies with IEC 62053-21, IEC 62053-22, IEC 62053-23 and IEC 62053-24. Nevertheless, uncertainties defined in this document for active and reactive energy measurement are derived from those defined in IEC 62053 (all parts);
– the measurement and monitoring of electrical parameters defined in IEC 61557-2 to IEC 61557-9 and IEC 61557-13 or in IEC 62020;
– power quality instrument (PQI) according IEC 62586 (all parts);
– devices covered by IEC 60051 (all parts) (direct acting analogue electrical measuring？ instrument). IEC 61557-12:2018 cancels and replaces the first 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) PMD-A has been withdrawn due the fact these devices are now mainly covered by the IEC 62586 series of standards.
b) Three categories of PMD have been created with a list of minimum required functions for each category.
c) Added a new Annex A explaining the different applications linked to the relevant standards and devices, and another new Annex C about the power factor conventions.