IEC 60794-1-211 pdf – Optical fibre cables – Part 1-211: Generic specification – Basic optical cable test procedures – Environmental test methods – Sheath shrinkage, method F11
1Scope
This part of lEC 60794 defines test procedures to measure the shrinkage of the sheath due tothermal exposure of cables.
Afirst test method,F11A, is included for cables where the fibre or buffered fibre and the sheathof the cable are intended to be fully terminated into a connector at one or both cable ends.
A second test method,F11B,is included in this document for sheath shrinkage testing forgeneral purpose.
See IEC 60794-1-2for a reference guide to test methods of all types and for generalrequirements.
Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.
For undated references,the latestedition of the referenced document(including anyamendments) applies.
IEC 60794-1-1，Optical fibre cables – Part 1-1: Generic specification – General
IEC 60794-1-22:2017，Optical fibre cables – Part 1-22: Generic specification – Basic opticalcable test procedures- Environmental test methods
3Terms and definitions
For the purposes of this document, the terms and definitions given in lEC 60794-1-1 apply.
ISO and lEC maintain terminological databases for use in standardization at the followingaddresses:
·IEC Electropedia: available at http://www.electropedia.orgl
.Iso Online browsing platform: available at http://www.iso.orglobp
4 Method F11A- Sheath shrinkage (cables to be terminated with connectors)
4.1Objective
The purpose of this test is to measure the shrinkage behaviour of the sheath due to thermalexposure of cables intended to be terminated with connectors.
This test is not intended for connectorised cable assemblies.
See Annex A for a comparison between method F11A and method F11B.
4.2sample
A2 m length of cable shall be cut from the end of the cable and discarded in order to avoid endeffects. The test sample lengths shall be cut from the adjoining cable.Five test samples of thelength specified in the detail specification shall be cut from the cable.
– For test samples of a nominal 1 m length, cut 1 050 mm ± 5 mm.- For test samples of a nominal length of 150 mm, cut 160 mm ± 5 mm.4.3Apparatus
A horizontal surface where the test samples are placed that permit free movement of the sheath.For example, talc, paper or paper dusted with talc on the surface permits free movement of thesheath.
A temperature chamber of appropriate size and a temperature sensing device.The temperaturechamber shall be able to accommodate the test samples and maintain the specified temperaturewithin +3℃.
A length measuring device of sufficient length with a minimum resolution of 1 mm for a samplewith a nominal 1 m length, or 0,15 mm for a sample with a nominal 150 mm length.
4.4 Procedure
The cable on the supply reel,or alternatively the cable coil, shall be conditioned for 24 h atambient temperature before cutting the test samples.
Two marks separated by the distance of the nominal test length per the detail specification (e.g.
1 000 mm，150 mm)，with a deviation not greater than ±1 mm,shall be applied to each testsample, as shown in Figure 1.
Alternatively, the sample ends may be cut to the measurement length, , using a razor knife.This alternative is best suitable for a short sample length of 150 mm.Two marks longitudinally
to the cable axis shall be applied to both ends of each test sample to indicate the measurementpoints, as shown in Figure 2.