IEC 60793-1-40:2019作为IEC 60793-1-40:2019 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 60793-1-40:2019建立了测量光纤衰减的统一要求，从而有助于检查商业用途的光纤和电缆。描述了用于测量衰减的四种方法，一种是用于建模光谱衰减的方法: -方法A:削减； -方法B:插入损失； -方法C:反向散射； -方法D:建模光谱衰减。 方法A至C适用于以下所有类别光纤的衰减测量: -A类多模光纤； -B类单模光纤。 方法C，反向散射，也涵盖了点不连续性的位置、损失和表征。方法D仅适用于B类纤维。所有四种方法共有的信息出现在第1至11条中，与每种方法相关的信息分别出现在附录A、B、C和D中。这第二版取消并取代了2001年出版的第一版。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)改进B6纤维测量细节的描述； b)改进A4纤维的校准要求； c)介绍附录E，描述A1多模光纤上的短电缆测试结果示例。 关键词:测量光纤的衰减

IEC 60793-1-40:2019 is available as IEC 60793-1-40:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60793-1-40:2019 establishes uniform requirements for measuring the attenuation of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. Four methods are described for measuring attenuation, one being that for modelling spectral attenuation:
– method A: cut-back;
– method B: insertion loss;
– method C: backscattering;
– method D: modelling spectral attenuation.
Methods A to C apply to the measurement of attenuation for all categories of the following fibres:
– class A multimode fibres;
– class B single-mode fibres.
Method C, backscattering, also covers the location, losses and characterization of point discontinuities. Method D is applicable only to class B fibres. Information common to all four methods appears in Clauses 1 to 11, and information pertaining to each individual method appears in Annexes A, B, C, and D, respectively. 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 changes with respect to the previous edition:
a) Improvement of the description of measurement details for B6 fibre;
b) Improvement of the calibration requirements for A4 fibre;
c) Introduction of Annex E describing examples of short cable test results on A1 multimode fibres.
Keywords: measuring the attenuation of optical fibre