scope:

IEC 60793-2-50:2015 is applicable to optical fibre categories B1.1, B1.2, B1.3, B2, B4, B5 and B6. A map illustrating the connection of IEC designations to ITU-T designations is shown in Annex I. 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 standard and which are given in Clause 5; - particular requirements applicable to individual fibre categories or specific applications, which are defined in Annexes A to G. 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. This fifth edition cancels and replaces the fourth edition, published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - aligns the requirements with the ITU-T Recommendations G.654 (2012-10) and G.657 (2012-10); - adds a new sub-category B1.2_d; - modifies B6 sub-categories in terms of attenuation and chromatic dispersion coefficient. Keywords: information transmission equipment, optical fibre cables