光纤电缆 第1-111部分：通用规范 基本光缆测试程序 机械测试方法 弯曲 方法 E11

[中文适用范围]： 本部分IEC 60794定义了确定光缆在测试心轴上弯曲能力的测试程序。本程序的主要目的是测量光缆在测试心轴上弯曲时的衰减变化。次要目的是评估光缆是否因弯曲而受到物理损伤。 注1：本测试可在任何指定温度下进行，包括光缆的低温或高温极限。 注2：光缆元件的弯曲测试程序在IEC 60794-1-301中规定，方法G1。 [外文原描述]： IEC 60794-1-111: 2023 defines the test procedure to determine the ability of an optical fibre cable to withstand bending around a test mandrel. The primary purpose of this procedure is to measure the change in attenuation when the cable is bent around a test mandrel. A secondary purpose is to assess whether the cable has been physically damaged by bending. NOTE 1 This test can be utilized at any specified temperature, including the low or high temperature limits for the cable. NOTE 2 The bend test procedure for cable elements is specified in IEC 60794-1-301, method G1. This document partially cancels and replaces IEC 60794-1-21:2015. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 60794‑1‑21:2015: a) the nominal sample length was newly specified as 10 m between the cable element fixing points at both ends, unless otherwise specified; b) the number of turns on the mandrel in Figure 1 for the single-helix configuration were corrected to match the number of turns shown in the figure for the two-helix configuration; c) requirements on the turnaround loop were added for method E11A, two-helix configuration; d) the turnaround loop with the same diameter as the mandrel was taken into account for calculation of the number of turns of each helix for method E11A, two-helix configuration; e) added a formula for calculation of the number of revolutions in each helix for method E11A, two-helix configuration; f) added a description for the procedure when the turnaround loop diameter is larger than the mandrel diameter for method E11A, two-helix configuration; g) all the figures were updated and the different components labelled; h) added the attenuation monitoring equipment in 4.2 for the apparatus and the description to measure the change in attenuation in the test methods E11A and E11B; i) added Clause 9 for details to be reported; j) added Annex A showing an example of a special mandrel to perform the bend test according to method E11A, two-helix configuration; k) added Annex B providing the rationale for the options of method E11A, two-helix configuration.