IEC 61753-052-3:2016包含了光纤衰减器满足的最低初始测试和测量要求以及严格程度，以便归类为满足在非受控环境中使用的单模光纤非连接固定衰减器设备的要求。IEC 60869-1包含光衰减器的通用规范。本文件中规定的光学性能仅与非连接配置的光学衰减器有关。第二版取消并取代了2001年出版的第一版。本版为技术修订版。与上一版相比，本版包括以下重大技术变更:重新考虑性能要求。 关键词:非连接固定衰减器装置，非受控环境中的U类

IEC 61753-052-3:2016 contains the minimum initial test and measurement requirements and severities which a fibre optic attenuator satisfies in order to be categorised as meeting the requirements of single-mode fibre non-connectorized fixed attenuator devices used in uncontrolled environments. IEC 60869-1 contains the generic specification of the optical attenuator. Optical performances specified in this document relate only to non-connectorized configurations optical attenuators. This second edition cancels and replaces the first edition published in 2001. This edition constitutes a technical revision. This edition includes the following significant technical change with respect to the previous edition: reconsideration of performance requirements. Keywords: non-connectorized fixed attenuator devices, Category U in uncontrolled environments