IEEE 1594:2008 pdf free download – IEEE Standard for Helically Applied Fiber Optic Cable Systems (WrapCable) for Use on Overhead Utility Lines
5.2.1.3.1 Test setup
The general arrangement to be used for the acolian 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 onwhich the wrap cable is installed(in the correct manner so as to simulate its installation on the line).Thetest section is contained between the two intermediate abutments. End and intermediate abutments need notbe separate units if the combined unit affords sufficient space for the setup. The fiber optic cable to betested should be cut a sufficient length beyond the intermediate abutments to allow removal of the cablecoverings and to allow access to the optical fibers. Suitable dead-end assemblies or end abutments areinstalled on ground wire or conductor to fit between the intermediate abutments. The test sample shall beterminated at both ends prior to tensioning in a manner such that the optical fibers cannot move relative tothe cable. The load during the test shall be monitored using a dynamometer, load cell,calibration beam, orother device.Some means should be provided to maintain constant tension to allow for temperaturefluctuations during the testing.The conductor or ground wire should be tensioned to 100% of its ratedmaximum installation tension.
In order to achieve repeatability of test results, the active span should be 20 m or more in length, with asuitable suspension assembly located approximately two-thirds of the distance between the two dead-endassemblies. Longer active andor back spans may be used.(See Figure A.1.)The suspension assembly shallbe supported at a height such that the static sag angle of the cable to the horizontal is 1 3/4± 3/4° in theactive span.
Means shall be provided for measuring and monitoring the mid-loop (antinode) vibration amplitude at afree loop, not a support loop.
An electronically controlled shaker shall be used to excite the cable in the vertical plane. The shakerarmature shall be securely fastcned to the cable so that it is perpendicular to the cable in the vertical plane.The shaker should be located in the span to allow for a minimum of six vibration loops between thesuspension assembly and the shaker.
The test length (i.e., between the dead-cnd assemblics) of the optical fiber shall be a minimum of 100 m.Toachieve this length several fibers may be spliced together. At least one fiber shall be tested from each buffertube or fiber bundle.Measurements should be made using a light source with a nominal wavelength of1l550 nm ± 20 nm for single-mode fibers and a nominal wavelength of 1300 nm ± 20 nm for multimodefibers.
The source shall be split into two signals. One signal shall be connected to an optical power meter and shallact as a reference. The other signal shall be connected to a free end of the test fiber. The returning signalshall be connected to a second optical power meter.All optical connections and splices shall remain intactthrough the entire 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 providesa reference level. The change in this difference during the test will indicate the change in attenuation of thetest fiber. The signals may be output on a strip chart recorder for a continuous hardcopy report.