prSSH EN IEC 60794-1-111:2024

Optical fibre cables - Part 1-111: Generic specification - Basic optical cable test procedures - Mechanical tests methods - Bend, method E11

Scope

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.