DIN EN IEC 60794-1-111:2024-07

This part of IEC 60794 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. The standard describes the test setup, pre-treatment, test conditions, monitoring, recovery time, final measurement, test severity, and measurement uncertainties, as well as details of the test report. The method is not applicable to individual elements of the cable. The bend test procedure for cable elements is specified in IEC 60794-1-301, method G1. The standard differs from DIN EN 60794‑1‑21 (VDE 0888-100-21):2021-03 as follows: 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. The application of this standard increases investment security for manufacturers and users and provides test laboratories and manufacturers with defined specifications for testing.