光纤 第1-40部分：衰减测量方法

[中文适用范围]： 本部分IEC 60793确立了测量光纤衰减的统一要求，从而有助于光纤和光缆的商业用途检查。描述了四种测量衰减的方法，其中一种是用于模拟光谱衰减的方法： - 方法A：截断法； - 方法B：插入损耗法； - 方法C：背向散射法； - 方法D：光谱衰减模拟法。 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（背向散射法）还包括点不连续性的定位、损耗和表征。 方法D仅适用于B类光纤。 所有四种方法的共同信息出现在第1条至第11条中，每种方法的具体信息分别出现在附录A、附录B、附录C和附录D中。 [外文原描述]： IEC 60793-1-40:2024 RLV contains both the official IEC International Standard and its Redline version. The Redline version 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 60793-1-40:2024 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 Clause 1 to Clause 11, and information pertaining to each individual method appears in Annex A, Annex B, Annex C, and Annex D, respectively. This third edition cancels and replaces the second edition published in 2019. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) modifying the definition of attenuation to be compatible with the definition in electropedia.org