光纤 第2-50部分：产品规范 B类单模光纤分规范

[中文适用范围]： IEC 60793-2-50:2025 CMV 包含官方标准及其注释版本。注释版本为您提供了一种快速简便的方法来比较 IEC 60793-2-50:2025 版本 7.0 和之前的 IEC 60793-2-50:2018 版本 6.0 之间的所有变化。此外，还提供了 IEC TC 86 专家的评论，以解释最相关变化的原因，或澄清内容的任何部分。 IEC 60793-2-50:2025 适用于光纤类别 B-652、B-653、B-654、B-655、B-656 和 B-657。表 1 显示了 IEC 名称与 ITU-T 名称之间的连接关系图。这些光纤用于或可并入信息传输设备和光纤电缆中。这些光纤有三种类型的要求： - 一般要求，如 IEC 60793-2 所定义； - 本文件中涵盖的 B 类单模光纤共有的特定要求，在第 4 条中给出； - 适用于个别光纤类别或特定应用的特殊要求，定义在附件 A 至附件 F 中。对于某些光纤类别（如相关系列规范中所示），存在根据传输属性规范的差异而区分的子类别。这些子类别的名称记录在各个系列的规范中。表 1 显示了从 IEC 名称到 ITU-T 建议的映射。第七版取消并取代了 2018 年发布的第六版。此版本构成技术修订。此版本相对于前一版本包括以下重大技术变化。 a) 附件 C 中为 B-654A、B、C 光纤增加了 200 µm 涂层标称外径选项 [外文原描述]： IEC 60793-2-50:2025 CMV contains both the official standard and its commented version. The commented version provides you with a quick and easy way to compare all the changes between IEC 60793-2-50:2025 edition 7.0 and the previous IEC 60793-2-50:2018 edition 6.0. Furthermore, comments from IEC TC 86 experts are provided to explain the reasons of the most relevant changes, or to clarify any part of the content. IEC 60793-2-50:2025 is applicable to optical fibre categories B-652, B-653, B-654, B-655, B‑656 and B-657. A map illustrating the connection of IEC designations to ITU-T designations is shown in Table 1. These fibres are used or can be incorporated in information transmission equipment and optical fibre cables. Three types of requirements apply to these fibres: - general requirements, as defined in IEC 60793-2; - specific requirements common to the class B single-mode fibres covered in this document and which are given in Clause 4; - particular requirements applicable to individual fibre categories or specific applications, which are defined in Annex A to Annex F. For some fibre categories (shown in the relevant family specifications), there are sub-categories that are distinguished on the basis of difference in transmission attribute specifications. The designations for these sub-categories are documented in the individual family specifications. Table 1 shows a map from the IEC designations to the ITU-T recommendations. This seventh edition cancels and replaces the sixth edition published in 2018. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition. a) The addition of a 200 µm coating nominal outer diameter option for B-654A, B, C fibres in Annex C