IEEE 1594:2020 pdf free download – IEEE Standard for Helically-AppliedFiber Optic Cable Systems (WRAP)for Use on Overhead Utility Lines
6.2.1.3 Aeolian vibration test
An aeolian vibration test shall be carried out.As the combinations of wrapped cables and ground wirelconductor/messenger wire are significant,a representative test can be performed for a family of cablecombinations.Any damage that will affect the mechanical performance of the cable or causes a permanentor temporary increase in optical attenuation greater than 1.0 dB/test fiber km (defined as the actual fiber inthe vibration test span) at 1550 nm±20 nm for single-mode fibers, or 1300 nm ±20 nm for multimode fibers,shall constitute failure.There shall be no breach of the jacket after the test. The objective of this test is toassess the fatigue performance of the WRAP cable and the ground wire on which it is installed and the opticalcharacteristics of the fibers under typical acolian vibrations.
6.2.1.3.1 Test setup
The general arrangement to be used for the aeolian vibration tests and the support details are shown in(Annex A). The end abutments are used to load and maintain tension in the conductor or ground wire on whichthe WRAPcable is installed (in the correct manner so as to simulate its installation on the line).The test sectionis contained between the two intermediate abutments.End and intermediatc abutments need not be separateunits if the combined unit affords sufficient space for the setup. The fiber optic cable to be tested shall be cuta sufficient length beyond the intermediate abutments to allow removal of the cable coverings and to allowaccess to the optical fibers.Suitable dead-end assemblies or end abutments are installed on ground wire orconductor to fit between the intermediate abutments. The test sample shall be terminated at both ends prior totensioning in a manner such that the optical fibers cannot move relative to the cable.The load during the testshall be monitored using a dynamometer, load cell, calibration beam, or other device. Some means shall beprovided to maintain constant tension to allow for temperature fluctuations during the testing.The conductoror ground wire shall be tensioned to 100% of its rated maximum installation tension.
In order to achieve repeatability of test results, the active span shall be 20 m or more in length, with a suitablesuspension assembly located approximately two-thirds of the distance between the two dead-end assemblies.
An electronically controlled shaker shall be used to excite the cable in the vertical plane.The shaker armatureshall be securely fastened to the cable so that it is perpendicular to the cable in the vertical plane.The shakershall be located in the span to allow for a minimum of six vibration loops between the suspension assemblyand the shaker.
The test length (i.e., between the dead-end assemblies) of the optical fiber shall be a minimum of 100 m.To achieve this length several fibers may be spliced together. At least one fiber shall be tested from eachbuffer tube or fiber bundle.Measurements shall be made using a light source with a nominal wavelength of1550 nm±20 nm for single-mode fibers and a nominal wavelength of 1300 nm±20 nm for multimode fibers.
The source shall be split into two signals. One signal shall be connected to an optical power meter and shal actas a reference.The other signal shal be connected to a free end of the test fiber. The returning signal shall beconnected to a second optical power meter. All optical connections and splices shall remain intact through theentire test duration.
An initial optical measurement shall be taken when the span is pre-tensioned to approximately 10% of themaximum installation tension. A second optical measurement shall be taken after final tensioning to themaximum installation tension. The difference between the two signals for the initial measurement provides areference level.The change in this difference during the test will indicate the change in attenuation of the testfiber. The signals may be output on a strip chart recorder for a continuous hardcopy report.