Optical cable

Historicalevolution

In1976,theBellInstituteoftheUnitedStatesbuiltthefirstopticalfibercommunicationexperimentalsysteminAtlanta,usinganopticalcablecontaining144opticalfibersmanufacturedbyWesternElectric.In1980,commercialopticalcablesmadeofmultimodeopticalfibersbegantobeusedoninter-officetrunklinesandafewlong-distancelinesinthecity.Commercialopticalcablesmadeofsingle-modeopticalfibersbegantobeusedonlong-distancelinesin1983.In1988,thefirsttrans-AtlanticsubmarinecableconnectingtheUnitedStatesandBritainandFrancewassuccessfullylaid,andsoonthefirsttrans-Pacificsubmarinecablewasbuilt.Chinadevelopeditsowncommunicationopticalcablein1978,whichusedmulti-modeopticalfiberwithastrandedcorestructure.FieldtestshavebeencarriedoutsuccessivelyinShanghai,Beijing,Wuhanandotherplaces.Soonafter,itwastriedoutasaninter-officetrunkinthelocaltelephonenetwork.After1984,itwasgraduallyusedforlong-distancelines,andsingle-modefiberwasadopted.Communicationopticalcableshavegreatertransmissioncapacitythancoppercables,withlongrelaysections,smallsize,lightweight,andnoelectromagneticinterference.Since1976,theyhavedevelopedlong-distancetrunklines,intra-cityrelays,offshoreandtransoceanicsubmarinecommunications.,Aswellasthebackboneofwiredtransmissionlinessuchaslocalareanetworksandprivatenetworks,andbegantodevelopintothefieldofuserloopdistributionnetworksinthecity,providingtransmissionlinesforfiber-to-the-homeandbroadbandintegratedservicedigitalnetworks.

Basicstructure

Opticalcableiscomposedofcablecore,reinforcedsteelwire,fillerandsheath.Inaddition,therearewaterprooflayer,bufferlayer,insulatedmetalwire,etc.asrequiredmember.

Theopticalcableiscomposedofthreeparts:astrengtheningcore,acablecore,asheathandanoutersheath.Thecablecorestructurehastwotypes:single-coretypeandmulti-coretype:single-coretypehastwotypes:substantialtypeandtubebundletype;multi-coretypehastwotypes:ribbontypeandunittype.Theoutersheathhastwotypes:metalarmoredandnon-armored.

Basiccommonsense

Basiccommonsenseisintroducedthroughlaying,type,construction,precautionsandthelimitofopticalfiber.Thespecificcontentisasfollows:

一,Laying

1.Generalregulations

1.1Thebendingradiusoftheopticalcableshouldnotbelessthan15timestheouterdiameteroftheopticalcable,anditshouldnotbelessthan20timesduringtheconstructionprocess.

1.2Thetractionforceoflayingouttheopticalcableshouldnotexceed80%oftheallowabletensionoftheopticalcable.Theinstantaneousmaximumtractionforceshallnotexceed100%oftheallowabletensionoftheopticalcable.Themaintractionshouldbeaddedtothestrengthmember(core)oftheopticalcable.

1.3Thetractionendoftheopticalcablecanbeprefabricatedormadeonsite.Directlyburiedorunderwaterarmoredopticalcablecanbeusedasanetsleeveortractionend.

1.4Inordertopreventtwistinganddamagetotheopticalcableduringthetowingprocess,aswivelshouldbeaddedbetweenthetowingendandthetowingrope.

1.5Whenlayingouttheopticalcable,theopticalcablemustbereleasedfromthetopofthecablereelandmaintainaslackarc.Thereshouldbenotwistingduringthelayingoftheopticalcable,anditisstrictlyforbiddentomakesmallloopsandsurges.

1.6Whenmechanicaltractionisusedforfiberopticcablelaying,centralizedtraction,intermediateauxiliarytractionordecentralizedtractionshouldbeselectedaccordingtofactorssuchastractionlength,terrainconditions,andtractiontension.

1.7Thetractorusedformechanicaltractionshouldmeetthefollowingrequirements:

1)Thetractionspeedadjustmentrangeshouldbe0-20m/min,andtheadjustmentmethodshouldbesteplessspeedregulation;

2)Thetractiontensioncanbeadjusted,andithasanautomaticstopfunction,thatis,whenthetractionforceexceedsthespecifiedvalue,itcanautomaticallysendanalarmandstopthetraction.

1.8Layingoutopticalcablesmustbecloselyorganizedanddirectedbyadedicatedperson.Thereshouldbegoodcommunicationmeansduringthetowingprocess.Itisforbiddenforuntrainedpersonneltogotoworkandworkwithoutcontacttools.

1.9Aftertheopticalcableislaidout,checkwhethertheopticalfiberisingoodcondition.Theendoftheopticalcableshallbesealedandmoisture-proof,andshallnotbeimmersedinwater.

2.Ductopticalcable

2.1Thefollowingpreparationsshouldbemadebeforelayingtheductopticalcable

1)Checkthepositionofthepipeholeoccupiedbytheopticalcableaccordingtothedesign;

2)Thepositionoftheholesselectedonthesamerouteshouldnotbechanged.Forexample,whenchangingorturning,theyshouldmeettherequirementsofthebendingradiusoftheopticalcable;

3)Theholesusedmustbecleaned.

2.2Eachentryholeshouldbeguardedwhenmanuallylayingtheopticalcable;whenturningtheentryholewhenmechanicallylayingtheopticalcable,thereshouldbesomeoneonduty.

2.3Whentheopticalcablepenetratesintothepipeholeorthepipeisbentorcrossed,aguidingdeviceorabellmouthprotectionpipeshallbeused,andtheouterprotectivelayeroftheopticalcableshallnotbedamaged.Aneutrallubricantcanbeappliedaroundthefiberopticcableasrequired.

2.4Thelengthofopticalfibercableisgenerallynotmorethan1000metersatatime.Whenthelengthistoolong,itshouldadopt8-charactersegmenttractionoraddauxiliarytractioninthemiddle.

2.5Afterthefiberopticcableislaidout,adedicatedpersonshallbeinchargeofuniformlyplacingthefiberopticcableontheprescribedpalletonebyoneintotheholes,andapropermarginshouldbelefttoavoidthefiberopticcablefrombeingtootight.

2.6Thereservedlengthoftheopticalcableattheentryholewheretheconnectorislocatedshouldmeettherequirementsinthetable;theopticalcablewithaspecialdesignrequirementistootight.

2.7Theprotectionmeasuresofthepipelineopticalcableshouldmeetthefollowingrequirements:

1)Theopticalcableintheholecanbeprotectedbyaserpentinehose(orsoftplastictube)andtiedtothecabletrayOntheboardoraccordingtothemeasuresrequiredbythedesign;

2)Thenozzleshouldbeblocked;

3)Theopticalcableintheholeshouldhaveidentificationmarks;

4)Inseverecoldareas,anti-freezingmeasuresshouldbetakenaccordingtodesignrequirementstopreventdamagetoopticalcables.

2.8Thelayingmethodofplasticsub-pipesisbasicallythesameasthelayingofopticalcables,andshouldalsomeetthefollowingrequirements:

1)Whenlayingtwoormoresub-pipeswithoutcolorcode,Marksshouldbemadeattheend;

2)Theambienttemperatureforlayingplasticsub-pipesshouldbebetween-5℃and+35℃;

3)ContinuouslayingofplasticThelengthofthesub-pipeshouldnotexceed300meters;

4)Themaximumpullingforceofthesub-pipeshouldnotexceedthetensilestrengthofthepipe,andthepullingspeedshouldbeuniform;

5)Theexcesslengthofthepipeintheinletholeshouldmeetthedesignrequirements;

6)Theplasticpipeplug(othermethodscanalsobeused)shouldbeinstalledintheholeoftheplasticsub-pipetofixthesub-pipe;

7)Thesub-pipesmustnothavejointsinthemiddleofthepipeline;

8)Afterthesub-pipesarelaidout,thenozzlesshouldbetemporarilyblocked;thesub-pipesnotusedintheprojectmustbeThepipeendisblocked(cap).

3.Directlyburiedopticalcable

3.1TheburieddepthoftheopticalcableshouldmeettherequirementsofTable3.1.

Layingsectionorsoilquality

Burieddepth(m)

Remarks:

Ordinarysoil(hardsoil)≥1.2

Semi-lithic(gravelsoil,weatheredstone)≥1.0

Allstone≥0.8

Calculatedfromthetopofthetrenchbottomwith10cmoffinesoil.

Quicksand≥0.8

Suburbs,villagesandtowns≥1.2

Urbansidewalks≥1.0

Crossingrailways,highways≥1.2

Distancefromballastbottomorroadsurface

Ditch,canal,pond≥1.2

Farmlanddrainageditch(ditchwidthwithin1meter)≥0.8

3.2Thedistancebetweenthedirectlyburiedopticalcableandotherbuildingsandundergroundpipelinesshallmeetthespecifiedrequirements.

3.3Opticalcableslaidinthesametrenchshouldnotbecrossedoroverlapped,andshouldbehauledseparatelyandlaidoutatthesametime.

3.4Thelayingofdirectlyburiedopticalcablesshouldmeetthefollowingrequirements:

1)Thedepthoftheopticalcabletrenchshouldmeettherequirements,andthebottomofthetrenchshouldbeflatandfreeofgravel;stone,semi-lithictrenchbottom10cmthickfinesoilorsandshouldbelaid;

2)Whenmechanicallytowing,groundpulleysshouldbeused;

3)Whenmanuallylifting,theopticalcableshouldnothaveacurvaturelessthanthespecifiedcurvatureRadiusbends,moppingoftheground,andexcessivetraction;

4)Theopticalcablemustbelaidflatatthebottomofthetrench,andmustnotbevacatedorarched;

5)Theopticalcablemustbelaidonaslopegreaterthan20°,whentheslopelengthisgreaterthan30metersontheslope,itisadvisabletoadoptthe"S"shapelayingorthemeasuresrequiredbythedesign;

6)Duringorafterlaying,theopticalcableshouldbecheckedintimeIftheouterskinisdamaged,itshouldberepairedimmediately;afterlayingthedirectlyburiedopticalcable,checktheinsulationresistanceoftheopticalcablesheathtotheground.

7)Theopticalfibersandcopperwiresintheopticalcablemustbeinspectedandconfirmedtomeetthequalityacceptancestandardsbeforetheycanbereturnedtothesoil.

3.5Thebackfilloftheopticalcabletrenchshouldmeetthefollowingrequirements:

1)Firstbackfill15cmthickcrushedsoilorfinesoil,anditisstrictlyforbiddentopushstones,bricks,frozensoil,etc.Intheditch,itshouldbeleveledmanually;

2)Thebackfillshouldbe10cmabovetheground.

3.6Protectivemeasuresforburiedopticalcablesshallbedesignedaccordingtothedesignregulationsandmeetthefollowingrequirements:

1)Whenopticalcablelinescrossrailwaysandhighwayswithoutexcavation,thepipejackingmethodshallbeadopted.Thepipejackingshouldbekeptstraightandthesteelpipespecificationsandpositionshouldmeetthedesignrequirements.Thepositionwherethesoilisallowedtobreakcanbeprotectedbyburiedpipes,andthenozzleshouldbeblockedwhenthepipeisjackedorburied.

2)Whenopticalcablelinespassthroughmechanicalfarmingroads,ruralavenues,urbanareas,residentialareasoreasilymovablelandsections,theyshouldbeconstructedinaccordancewiththeprotectionmethodsrequiredbythedesign.Whenlayingredbricksontopoftheopticalcables,coverwith20cmthicksoilbeforelayingredbricksvertically.Forlayingtwoopticalcablesinthesametrench,redbricksshouldbelaidhorizontally.

3)Whentheopticalcablelinepassesthroughtheditch,canalorpondwithdredginganddredgingforfertilizer,thetopoftheopticalcableshouldbecoveredwithcementboardorcementsandbagforprotection.

4)Slopeprotectionshouldbeusedwhentheopticalcablepassesthroughtheditchandterraceof0.8metersormore(including0.8meters),andtheslopeprotectionmethodshouldbeinaccordancewiththedesignrequirements.Whencrossingditchandridgebelow0.8meters,exceptforspecialdesignrequirements,slopeprotectionisgenerallynotused,butitmustbetampedandrestoredinlayers.

5)Thefiberopticcablelinepassingthroughthetermiteactivityareashouldbetreatedwithanti-termitesinaccordancewiththeregulations.

6)Lightningprotectionmeasuresforopticalcablelinesmustbedealtwithinaccordancewithdesignregulations.Whenusinglightningprotectiondrainagelines,singleordoubledrainagelinesshouldbelaid30cmabovetheopticalcable;whentheopticalcableisdugoutforre-layingafterbackfilling,itisnecessarytostrictlycheckwhetherthedrainagelineisabovetheopticalcable.Reversalphenomenonisstrictlyprohibited.

7)Thelayingofthemarkingtapeinthespecialareashallmeetthedesignrequirements.

3.7Thereservedopticalcableatthejointpointshouldbeproperlyplacedinthejointpit,andtheendmustbesealedandmoisture-prooftopreventtheopticalcablefrombeingimmersedinwaterorartificiallydamaged.

3.8Theburyingofopticalcablelinemarkersshallmeetthefollowingrequirements:

1)Opticalcablejoints,opticalcableturningpoints,drainlinestartandendpoints,startandendpointsofopticalcableslaidinthesametrench,opticalcablesSpecialreservedpoints,crossingpointswithothercables,crossingobstacles,andstraightsectionsofurbanareasshallbesetatintervalsof200meters,suburbanareasandlongdistancesatintervalsof250meters.

2)Thejointpointsthatneedtomonitortheinsulationandpotentialofthemetalsheathintheopticalcableshouldbesetwithmonitoringmarkers.

3)Whenthereisamarkthatcanbeused,afixedmarkcanbeusedinsteadofthemarkstone.

4)Theburieddepthofthemarkerstoneis60cmand40cmisunearthed.Thesoilaroundthemarkerstoneshouldbecompacted.

5)Ordinarymarkersshouldbeburieddirectlyabovetheopticalcable.Themarkingstoneatthejointshouldbeburiedintherouteoftheopticalcableline,andthesidewiththemarkingstoneshouldfacetheopticalcablejoint.Themarkingstoneattheturningpointshouldbeburiedattheintersectionoftheopticalcableline,andthemarkingstoneshallfacethesidewiththesmallerangleoftheopticalcable.Whenthedistancebetweentheopticalcableslaidalongthehighwayisnotmorethan100meters,themarkerscanfacethehighway.

6)Themarkerstonesaremadeofhardstoneorreinforcedconcrete,andtherearetwospecifications:shortmarkerstonesareusedingeneralareas,andthesizeshouldbe100×14×14cm;softsoilandslopeareasuselongmarkerstones,Thespecificationis150×14×14cm.

7)Thenumberofthemarkerstonesisred(orblack)lacqueredblocklettersonawhitebackground,thefontiscorrect,andthesurfaceistidy.ThenumbershouldbearrangedfromendAtoendBaccordingtothedirectionoftransmission.Generally,ahopisanindependentnumberingunit.

4.Underwateropticalcable

4.1Thelayingmethodofunderwateropticalcableshouldbebasedonthesoilqualityoftheriverbed,thewidthoftheriver,thewaterdepth,theflowvelocityandthesiteconditions.Differentmethodssuchasflushpumpgrooving,anchordroppingslowrelease,tugfastrelease,manualplacement,etc.,nomatterwhatconstructionmethodisused,shouldmeetthedesignrequirements.

4.2Theburieddepthoftheunderwateropticalcableshouldbebasedonthespecificconditionsoftheriver'swaterdepth,navigation,andriverbedsoilquality,asspecifiedinthedesigndocuments,andshouldmeetthefollowingrequirements:

1)InsufficientwaterdepthSectionof8meters(referringtothedryseason):whentheriverbedisunstableorthesoilissoft,theburieddepthshouldbenolessthan1.5meters;whentheriverbedisstableorthesoilishard,theburieddepthshouldbenolessthan1.2meters;thestoneandsemi-lithicriverbed,Theburialdepthshouldnotbelessthan0.5meters;

2)Sectionswithawaterdepthofmorethan8meters:Generally,theopticalcablecanbeplaceddirectlyatthebottomoftheriverwithoutburial,andspecialsectionsshallbetreatedaccordingtotherequirementsofthedesigndocuments.

4.3Thelayingofunderwateropticalcablesshallmeetthefollowingrequirements:

1)Thelayingspeedandspecifiedpositionoftheopticalcableshallbecontrolled;

2)Duringthelayingprocess,theopticalcableshallnotbeDonotmakesmallcircleswhentheriverbedisvacated;

3)Duringandafterthelaying,theopticalfibershouldbemonitoredforgoodquality,andanyproblemsshouldbedealtwithintimetoensurethelayingqualityoftheunderwateropticalcable;

4)Thelayinglengthshouldbeaccordingtothelengthoftheopticalcabledeterminedduringthere-measurementoftheroute.Generally,theunderwateropticalcableshouldextend50metersbeyondtheembankmentorthebank;5)Whenthedesignstipulatesthattheopticalcableislaidinanarcatthebottomoftheriver,Thebaselineduringthemeasurementshouldbeusedasthebenchmark,andthearclayingshouldbedoneupstream.

4.4Theburieddepthandprotectionofthebeachshouldmeetthefollowingrequirements:

1)Theburieddepthofthebeachshouldnotbelessthan1.5meters.Forrockyandsemi-lithicareas,fillthebottomofthetrenchwith10-20cmoffinesoilorsand,andbackfillthetopoftheopticalcablewithcrushedsoilorsand,andthenfillitupabovethegroundaftertamping.Forbeachesthatarescouredbyfloods,unstableareasandshipsdockingareas,afterfillingthetopofthefiberopticcablewithcrushedsoilorsand,itshouldbecoveredwithcementboardorcementsandbagsforprotection.

2)Thebankslopeshouldbelessthan30degrees,andwhenitexceeds,reinforcementmeasuresshouldbetakenaccordingtothedesignrequirements.

4.5Fornavigableriverswhereunderwateropticalcablesarelaid,areaswhereanchoringisprohibitedshallbedelineatedaccordingtothedesignrequirements,andwaterlinesignsshallbesetupontheembankmentsorbanksoftherivercrossingsections,andshallmeetthefollowingrequirements:

1)Thewaterlinesignsshouldbesingle-poleordouble-polesignsaccordingtothedesignrequirementsorthesizeoftheriver,andshouldbeinstalledinthedesignatedpositionbeforethewaterlineislaid;

2)Thewaterlinesignshouldbeinstalledinaplacewithhighterrainandnoobstruction,andthefrontofthesignshouldbeatanangleof250-300totheupstreamordownstreamdirection;

3)ThewaterlinesignWhenitisinstalledinasoftsoilareaortheburieddepthisnotuptothestipulation,acableshouldbeadded,andachassis,achuckandotherreinforcementmeasuresshouldbeaddedtotherootofthecementpole.

5.Aerialopticalcable

5.1Thesagofaerialopticalcableshouldbedeterminedwithgreatcare.Itisnecessarytoconsiderthattheelongationrateoftheopticalcablewhenitissubjectedtothemaximumloadduringandafterinstallationshouldbelessthan0.2%.Intheproject,thesagoftheaerialopticalcableshouldbecalculatedaccordingtothecablestructureandthewayofhanging,andtheelongationoftheopticalcableshouldbecalculated,sothattheselectedsagoftheopticalcablecanensurethattheelongationoftheopticalcabledoesnotexceedthespecifiedvalue.

5.2Thelayingofaerialopticalcablesshouldbepulledbypulleys,andexcessivebendingisnotallowedduringthelayingprocess.

5.3Hangingoverheadopticalcablesshouldbereservedoneachpolefordeploymentinthemedium-loadarea,heavy-loadareaandover-loadarea.Keep.

5.4Thehangingtypeaerialopticalcableshouldbeadjusteduniformlyafterlaying,andthehookingprogramcanbeselectedaccordingtotheouterdiameteroftheopticalcablewithreferencetoTable5.4.Thehangingdistanceoftheopticalcablehookis50cm,andtheallowabledeviationshouldnotexceed±3cm.Thebuckledirectionofthehookonthehangingwireshouldbethesame,andthehookpalletshouldbecomplete.

Hookingprogramselectiontable5.4

Hookingprogramcableouterdiameter(mm)

6532ormore

5525～32

4519～24

3513～18

2512andbelow

5.5HangingoverheadopticalcableinstallationWaysandrequirements.

5.6Theanti-strongcurrentandlightningprotectionmeasuresoftheaerialopticalcableshallmeetthedesignrequirements.Whenthehangingoverheadopticalcablecrossesthepowerline,thesteelstrandshouldbeinsulatedwithhoseorbamboo.Thecontactpartoftheopticalcablewiththetreeshouldbeprotectedbyarubbertubeoraserpentinetube.

6.Intra-officeopticalcable

6.1Intra-officeopticalcableisgenerallyledtotheopticaltransceiverfromtheentranceholeinthefrontoftheofficethroughtheundergroundentranceroom.Duetothecomplexityofrouting,manualdeploymentshouldbeused.Whenlayingdownthecorridorsandateachcorner,adedicatedpersonshouldbeassignedtotractionaccordingtoaunifiedcommand.Keeptheopticalcableinaslackstateduringthetraction,anditisstrictlyforbiddentomakesmallcirclesanddeadbends.

6.2Intra-officeopticalcablesshouldbemarkedforidentification.

6.3Theopticalcableshouldchooseasafelocationintheincomingroom,andwhenitisinalocationvulnerabletoexternaldamage,protectivemeasuresshouldbetaken.

6.4Theopticalcableshouldbeboundthroughthecablerackandtheturningpoints(frontandrear).Thebindingpartsoftheupperandlowerwalkwaysorclimbingwallsshouldbelinedwithrubberhosestoavoidlateralpressureontheopticalcables.

6.5Theopticalcablereservedontheterminalsideaccordingtotheregulationscanbeleftintheopticalterminalroomorcableentryroom.Theopticalcablesreservedforspecialrequirementsshouldbereservedaccordingtothedesignrequirements.

7.Manufactureofopticalcable

Themanufacturingprocessofopticalcableisgenerallydividedintothefollowingprocesses:

1.Screeningofopticalfiber:selectexcellenttransmissioncharacteristicsandqualifiedtensionOpticalfiber.

2.Dyeingofopticalfiber:Usestandardfullchromatogramtomark,anditisrequiredthathightemperaturedoesnotfadeormigrate.

3.Secondaryextrusion:selecthighelasticmodulus,lowlinearexpansioncoefficientplastictoextrudeintoatubeofacertainsize,puttheopticalfiberintoandfillitwithmoisture-proofandwaterproofgel,andstoreitforafewdays(Notlessthantwodays).

4.Opticalcablestranding:strandingseveralextrudedopticalfiberswiththestrengtheningunit.

5.Squeezetheoutersheathoftheopticalcable:addalayerofsheathtothestrandedopticalcable.

Second,type

1.Accordingtodifferenttransmissionperformance,distanceandpurpose,opticalcablescanbedividedintouseropticalcables,localtelephoneopticalcables,long-distanceopticalcablesandsubmarinecables.Opticalcable.

2.Accordingtothedifferenttypesofopticalfibersusedinopticalcables,opticalcablescanbedividedintosingle-modeopticalcablesandmulti-modeopticalcables.

3.Accordingtothenumberoffibercoresinthefiberopticcable,thefiberopticcablecanbedividedintosingle-corefiberopticcable,dual-corefiberopticcableandsoon.

4.Accordingtothedifferentreinforcementconfigurationmethods,opticalcablescanbedividedintocentralstrengtheningmemberopticalcables,dispersedstrengtheningmemberopticalcables,sheathstrengtheningmemberopticalcablesandintegratedoutersheathopticalcables.

5.Accordingtodifferenttransmissionconductorsandmediumconditions,opticalcablescanbedividedintometal-freeopticalcables,ordinaryopticalcables,andintegratedopticalcables(mainlyusedforrailwaydedicatednetworkcommunicationlines).

6.Accordingtodifferentlayingmethods,opticalcablescanbedividedintopipelineopticalcables,directlyburiedopticalcables,overheadopticalcablesandunderwateropticalcables.

7.Accordingtodifferentstructuralmethods,opticalcablescanbedividedintoflatstructureopticalcables,strandedopticalcables,skeletonopticalcables,armoredopticalcablesandhigh-densityuseropticalcables.

Three.Construction

Overtheyears,wehavedevelopedasetofmaturemethodsandexperienceintheconstructionofopticalcables.

Useofopticalcabletool:

1Double-portfiberstrippingpliers,1strippingopticalfibercoating/tightcladding

2Installationof1setofcombinationsocketwrenchOpticalcableconnectionbox/terminalbox

32mtapemeasure,1piecetomeasurethelengthofthestrippedopticalcable

4Utilityknife,1pieceofauxiliarytoolforstrippingtheopticalcable

5Snake-headpliers1cutoffthefiberopticcablereinforcingcore

6horizontalcablecutters,1verticalhorizontalstrippingcable

7tweezers,1coiledfiber

8scissors,1cutterOpticalfiber

9vise1cutoffthesteelwireintheopticalcable

10needle-nosepliers1spliceauxiliarytool

11miniscrewdriver2fasteningscrewsUse

1setof12hexagonalwrenchtoinstallsixscrews

13Adjustablewrench,1connectionauxiliarytool

14Combinationscrewdriver,2installationandremovalofopticalcableconnectionBox

15alcoholpumpbottle,1cleaningfiber

16markerpen,1markingfibernumber

17flashlight1fornightconstructionlighting

18Diagonalpliersand1auxiliaryconstructiontool

(1)Outdoorconstructionofopticalcable

Themostimportantthingforthelayingoflongerdistanceopticalcableistochooseasuitablepath.Hereisnotnecessarilytheshortestpathisthebest,butalsopayattentiontotherighttousetheland,thepossibilityoferectionorburial,etc.

Whentheopticalcableturns,itsturningradiusmustbegreaterthan20timesthediameteroftheopticalcableitself.

1.Outdooroverheadfiberopticcableconstruction:

A.Suspendedwiresupportisusedtohangoverhead.Thismethodissimpleandcheap.Itisthemostwidelyusedinmycountry,butittakestimetoaddhooksandarrangethem.

B.Hangingwirewindingoverheadmethod,thismethodismorestableandrequireslessmaintenance.Butaspecialwrappingmachineisrequired.

C.Self-supportingoverheadmethod,whichhashighrequirementsforpoles,isdifficulttoconstructandmaintain,andhashighcost.ItisrarelyusedinChina.

D.Whenoverhead,aguidedevicemustbeinstalledatthepolewherethefiberopticcableisledtoavoiddraggingthegroundbythefiberopticcable.Payattentiontoreducingthefrictionwhentheopticalcableistowed.Alengthoffiberopticcablefortelescopingshouldbeleftoneachpole.

E.Payattentiontothereliablegroundingofmetalobjectsintheopticalcable.Especiallyinmountainousareas,high-voltagepowergridareasandareaswithheavythunderstorms,therearegenerally3groundingpointsperkilometer,andnon-metallicopticalcablesareevenused.

2.Outdoorpipelinefiberopticcableconstruction

A.Beforeconstruction,checktheoccupancyofthepipeline,cleanandplacetheplasticsub-pipes,andputinthetractionlineatthesametime.

B.Calculatethedeploymentlength,andtheremustbeenoughreservedlength.Seethetablebelowfordetails:

Intothehole

C.Donotdeploytoolongatatime(generally2KM).Whenwiring,startfromthemiddletobothsides.

D.Cabletractionisgenerallynotmorethan120kg,andthereinforcedcorepartoftheopticalcableshouldbehauled,andtheheadoftheopticalcableshouldbewaterproofandstrengthened.

E.Thelead-inandlead-outpointsoftheopticalcablemustbeequippedwithacollocationdevice,andthegroundcannotbedirectlymopped.

D.Ductopticalcablesshouldalsobegroundedreliably.

3.Directlyburiedopticalcablelaying

A.Directlyburiedopticalcabletrenchdepthshouldbeexcavatedaccordingtothestandard,thestandardisshowninthefollowingtable:

B.CannotdigtrenchesPlaceswherepipelinescanbelaidoverheadorboredandembedded.

C.Thebottomofthetrenchshouldbesmoothandfirm,andapartofsand,cementorsupportcanbepre-filledwhenneeded.

D.Manualormechanicaltractioncanbeusedwhenlaying,butattentionshouldbepaidtoguidanceandlubrication.

E.Afterthelayingiscompleted,thesoilshouldbecoveredandcompactedassoonaspossible.

4.Layingofopticalcablesinbuildings

A.Whenlayingvertically,specialattentionshouldbepaidtotheload-bearingproblemofopticalcables.Generally,theopticalcablesshouldbefixedonceeverytwolayers.

B.Whentheopticalcablepassesthroughthewallorthefloor,aprotectiveplasticpipewithaprotectivemouthshouldbeadded,andthepipeshouldbefilledwithflame-retardantfiller.

C.Acertainamountofplasticpipescanalsobelaidinthebuildinginadvance,andwhentheopticalcableistobelaidinthefuture,theopticalcablecanbelaidoutbytractionorvacuum.

Four.Precautions

1.Aftertheuserreceivestheopticalcable,checktheopticalcablecertificateandtheopticaldataprovidedwiththeopticalcable,andchecktheopticalcablereelnumber,model,Thenumberofcoresandlength,etc.,andchecktheouterpackagingfornobreakageloss.

2.Whentheopticalcableislaidout,atractionropemustbeusedtoconnectwiththeopticalcablereinforcement,andbefixedwithanetsleeveortapetothesheath.Ifitisapipelineopticalcable,aspecialrotatingtractionheadmustbeaddedbetweenthetractionropeandtheopticalcablereinforcement,anditisnotallowedtopulltheoutersheathoftheopticalcabledirectly.

3.Forthedeploymentofopticalcableswithalengthofmorethan2KM,itisnotallowedtoputtheopticalcablefromthebeginningtotheendatonetime.Itisnecessarytoplacetheopticalcableinthemiddleofthelotandplaceitinaninvertedfigure-eightshapeatbothends.

4.Whenunloadingthefiberopticcablefromthecar,itisbesttouseaforkliftorcranehoisttogentlyplacethefiberopticcablefromthecarontheground

5.UnloadthefiberopticcablefromthecarinfieldconstructionoccasionsItisadvisabletouseastraightboardtobeplacedbetweenthecarplatformandthegroundtoforma45-degreeslope.Usearopetopassthroughthemiddleholeoftheopticalcable.Whenapersonpullsbothendsoftheropeonthecar,theopticalcableslidesdowntheslopeofthewoodenboard.Whenunloadingopticalcables,stackthemcarefullyandlaythemflat.Itisstrictlyforbiddentodroptheopticalcablesdirectlyfromahighplace,andplacetheopticalcableswithstrongimpacttocausedamage.

6.Whentheopticalcableneedstoberolled,itshouldberolledinthedirectionoftherotationarrowmarkedonthecablereel,butlong-distancerollingisnotallowed.

7.Itisnecessarytocarryoutsingle-discinspectionoftheopticalcablebeforeconstruction,suchasthequalityoftheoutersheathandtheattenuationindex.

8.Themaximumtensileforcewhenlayingapipelineoroverheadopticalcabledoesnotexceed1500N,andthemaximumtensileforcewhenlayingdirectlyburiedopticalcabledoesnotexceed3000N.

9.Whentheopticalcableisconstructedandpositioned,itmustnotbebentorforma90-degreeright-anglebend;fordynamicbending(suchasduringconstruction),thebendingradiusofthepipeandoverheadopticalcableshouldbegreaterthan20timestheouterdiameteroftheopticalcable;Fordirectlyburiedopticalcables,thebendingradiusshouldbegreaterthan25timestheouterdiameteroftheopticalcable;whenlayingandpositioning,forpipelinesandoverheadopticalcables,thebendingradiusshouldbegreaterthan10timestheradiusoftheopticalcable;fordirectburiedopticalcables,thebendingradiusshouldbegreaterthan12.5timestheouterdiameteroftheopticalcable.Donotseverelybendtheopticalcableandcause"deadbutton".

10.Whentheopticalcableisconstructed,thetensileforceshallnotexceedtheallowableshort-termforcethatitcanbear(pipe,overheadopticalcable:1500N;directburiedopticalcable:3000N;ADSSopticalcable:20%RTS),anduseitinoperationItshouldnotexceedtheallowablelong-termforce(pipeline,overheadopticalcable600N;directburiedopticalcable1000N;ADSSopticalcable:MAT).Opticalcableconstructionshouldbecarriedoutundertheguidanceofappropriatelyqualifiedtechnicians.

Itisveryimportantforopticalcablestobewiredinthecorrectway.Improperconstructioncaneasilycauseincreasedattenuation,shortenedservicelife,fiberbreakage,brokenskin,andbrokenarmor.Opticalcables,especiallyfeedercables,havealargerdiameterandheavierquality.Whenlayingoutcables,youmustuseabrackettomountthecablereel,andpullthecablewhilerollingthecablereel.Ifitisaloosecablethatisnotequippedwithanopticalcablereel,besuretotakecareofit.Wirethecablesinthefuture.Thewirepullersandthedefendersmustbeequippedwithwalkie-talkiestokeepintouch.Don’tpullwithbruteforcewhentheycan’tpullthem.Theymustbesortedoutslowlybeforecontinuing,soastoensurethatour"fragile"opticalcablesarecovered.Safedeployment.

Five.Cablelimit

Allowabletensileforceandflatteningforce

SeetheallowabletensileforceandflatteningforceofopticalcableTable1.

Table1-Themechanicalpropertiesofopticalcableallowabletensileforceandflatteningforce

Connectionmethod

ThemethodismainlypermanentConnection,emergencyconnection,activeconnection.

1.Permanentopticalfiberconnection(alsocalledhotmelt)

Thiskindofconnectionistomelttheconnectionpointoftwoopticalfibersandconnectthemtogetherbymeansofelectricdischarge.Generallyusedinlong-distanceconnection,permanentorsemi-permanentfixedconnection.Itsmainfeatureisthattheconnectionattenuationisthelowestamongallconnectionmethods,withatypicalvalueof0.01~0.03dB/point.However,whenconnecting,specialequipment(fusionsplicer)andprofessionalsarerequiredtooperate,andtheconnectionpointneedstobeprotectedbyaspecialcontainer.

2.Emergencyconnection(alsocalled)coldmelt

Emergencyconnectionismainlytousemechanicalandchemicalmethodstofixandbondtwoopticalfiberstogether.Themainfeatureofthismethodisthattheconnectionisfastandreliable,andthetypicalattenuationoftheconnectionis0.1~0.3dB/point.However,theconnectionpointwillbeunstableforlong-termuse,andtheattenuationwillincreasegreatly,soitcanonlybeusedforemergencyinashorttime.

3.Activeconnection

Activeconnectionisamethodofconnectingthesitetothesiteorthesitetotheopticalcablebyusingvariousopticalfiberconnectiondevices(plugsandsockets).Thismethodisflexible,simple,convenient,andreliable,andismostlyusedincomputernetworkwiringinbuildings.Itstypicalattenuationis1dB/connector.

Selection

Inadditiontothenumberoffibercoresandfibertypes,theselectionoftheopticalcableshouldalsobebasedontheuseenvironmentoftheopticalcabletochoosetheoutersheathoftheopticalcable.

1.Whentheoutdoorfiberopticcableisdirectlyburied,itisbettertousearmoredfiberopticcable.Whenoverhead,ablackplasticoutersheathedopticalcablewithtwoormorereinforcingribscanbeused.

2.Whenselectingopticalcablesusedinbuildings,payattentiontotheirflameretardant,toxicandsmokecharacteristics.Generally,flame-retardantbutsmoke-freetypes(Plenum)canbeusedinductsorforcedventilation,andflame-retardant,non-toxicandsmoke-freetypes(Riser)shouldbeusedinexposedenvironments.

3.Whenlayingcablesverticallyinthebuilding,youcanuseDistributionCables;forhorizontalwiring,youcanchooseBreakoutCables.

4.Ifthetransmissiondistanceiswithin2km,multi-modefiberopticcablecanbeselected,andrelayorsingle-modefiberopticcablecanbeusedformorethan2km.

Standardforburieddepthofdirectburiedopticalcable

Layingsectionorsoilburieddepth(m)Remarks

Ordinarysoil(hardsoil)≥1.2

Semi-lithic(gravelsoil,weatheredstone)≥1.0

Totalstone≥0.8Add10cmfinesoilorsandfromthebottomoftheditch

Quicksand≥0.8

Suburbs,villagesandtowns≥1.2

Intra-citysidewalks≥1.0

Crossingrailways,highways≥1.2Distancetothebottomoftheballastorawayfromtheroad

Ditchesandcanals,Pond≥1.2

Farmlanddrainageditch≥0.8

Modelidentification

Example:

Thefirstpart

Classificationcode

Note:Betweenthefirstpartandthesecondpart:thecodenameofthereinforcingmember(reinforcingcore)

ThereinforcingmemberreferstotheinsideofthesheathorembeddedinthesheathtoenhancethetensilestrengthoftheopticalcableForcemembers:

Unsigned-metalreinforcedmember;G-metalheavy-dutyreinforcedmember

F-non-metallicreinforcedmember;H-non-metalheavy-dutyreinforcedmember

(forexample:GYTA:metalreinforcedcore;GYFTA:Non-metallicreinforcedcore)

Thecodeofthefillingstructurefeatureinthecablecoreandtheopticalcable

Thestructuralfeatureoftheopticalcableshouldindicatethemaintypeofthecablecoreandthederivativestructureoftheopticalcable.Whentheopticalcabletypehasseveralstructuralfeaturesthatneedtobenoted,itcanbeindicatedbythecombinationcode.

PartTwo

PartIII

SheathThecodename

Thefourthpartandthefifthpart

Thecodeofthefifthpartisrepresentedbytwosetsofnumbers.Onegrouprepresentsthearmorlayer,whichcanbeoneortwodigits;thesecondgrouprepresentsthecoatinglayer,whichisonedigit.

Codeofthearmorlayer

Coatinglayercode

PartVI

Opticalcablespecifications

Amultimodefiber

Bsinglemodefiber

Note:Multimodefibercannotcarryoutlong-distanceopticaltransmissionduetointer-modedispersion,anditisalmosteliminated.

Opticalfiberinspection

Themainpurposeofopticalfiberinspectionistoensurethequalityofthesystemconnection,reducefailurefactorsandfindoutthefaultpointoftheopticalfiberwhenitfails.Therearemanydetectionmethods,mainlydividedintomanualsimplemeasurementandprecisioninstrumentmeasurement.

1.Manualsimplemeasurement

Thismethodisgenerallyusedtoquicklydetecttheon-offofthefiberandtodistinguishthefibermadeduringtheconstruction.Itusesasimplelightsourcetoentervisiblelightfromoneendoftheopticalfiberandobservewhichoneemitslightfromtheotherend.Althoughthismethodissimple,itcannotquantitativelymeasuretheattenuationoftheopticalfiberandthebreakpointoftheopticalfiber.

2.Precisioninstrumentmeasurement

Useanopticalpowermeteroranopticaltimedomainreflectometer(OTDR)toquantitativelymeasuretheopticalfiber,andmeasuretheattenuationoftheopticalfiberandtheattenuationoftheconnector,Eventhebreakpointpositionofthefibercanbemeasured.Thismeasurementcanbeusedtoquantitativelyanalyzethecausesoffailuresinopticalfibernetworksandtoevaluateopticalfibernetworkproducts.

Identifytheprosandcons

1.Outer:Indooropticalcablesgenerallyusepolyvinylchlorideorflame-retardantpolyvinylchloride,andtheirappearanceshouldbesmooth,bright,flexible,andeasytopeeloff.Theouterskinofpoorqualityopticalfibercableisnotsmoothandeasytoadheretothetightsleeveandaramidinside.

ThePEsheathoftheoutdooropticalcableshouldbemadeofhigh-qualityblackpolyethylene.Afterthecableisformed,theouterskinissmooth,bright,uniforminthickness,andfreeofsmallbubbles.Theouterskinofinferiorfiberopticcableisgenerallyproducedwithrecycledmaterials,whichcansavealotofcost.Theouterskinofsuchfiberopticcableisnotsmooth.Becausetherearemanyimpuritiesintherawmaterial,theouterskinofthemadefiberopticcablehasmanyverysmallpits.water.

2.Opticalfiber:FormalopticalfibercablemanufacturersgenerallyuseA-gradecoresfromlargefactories.Somelow-costandinferioropticalcablesusuallyuseC-grade,D-gradeopticalfibersandsmuggledopticalfibersfromunknownsources.Theseopticalfibersareduetotheirsources.Itiscomplicated,ittakesalongtimetoleavethefactory,itisoftendampanddiscolored,andsingle-modefibersareoftenmixedinmultimodefibers.Generally,smallfactorieslackthenecessarytestingequipmentandcannotjudgethequalityofthefiber.Becausesuchopticalfiberscannotbedistinguishedbythenakedeye,thecommonproblemsencounteredinconstructionare:narrowbandwidthandshorttransmissiondistance;uneventhicknessandcannotbeconnectedtothepigtail;theopticalfiberlacksflexibilityandbreakswhenthefiberisbent.

3.Reinforcedsteelwire:Thesteelwireoftheoutdooropticalcableoftheregularmanufacturerisphosphated,andthesurfaceisgray.Suchsteelwiredoesnotincreasehydrogenloss,rust,andhashighstrengthafterbeingcabled.Inferiorfiberopticcablesaregenerallyreplacedbythinironoraluminumwires.Theidentificationmethodiseasy-itiswhiteinappearanceandcanbebentatwillwhenitispinchedinthehand.Theopticalfibercableproducedwithsuchsteelwirehasalargehydrogenloss,andafteralongtime,thetwoendsofthehangingopticalfiberboxwillrustandbreak.

Four.Steelarmor:Regularproductioncompaniesusedouble-sidedbrushedanti-corrosionpaintlongitudinallywrappedpatternsteelstrips,inferioropticalcablesaremadeofordinaryironsheet,usuallyonlyonesideistreatedwithrustprevention.

V.Loosetube:TheloosetubeoftheopticalfiberintheopticalcableshouldbemadeofPBTmaterial,whichhashighstrength,nodeformation,andanti-aging.InferiorfiberopticcablesgenerallyusePVCasthesleeve.Theouterdiameterofsuchasleeveisverythin,anditisflattenedbypinchingitbyhand.Itisabitlikeastrawfordrinkingbeverages.

6.Ointment:Ointmentmainlyincludesfiberpasteandcablepaste.Undernormalcircumstances,thefiberpasteshouldfilltheentireloosetube,andthecablepasteshouldfilleverygapoftheopticalcablecoreunderpressure.Therearewaystofillthefiberpastehalffullorless,whilesomeofthecablepastejustapplyalayerontheoutsideofthecablecore,andsomearenotfilledbetweenthetwoendsoftheopticalcable.Thiswillmaketheopticalfibernotwellprotected,affectthetransmissionperformancesuchasopticalfiberattenuation,andthepoorwaterproofperformancecannotreachthenationalstandard.Oncetheopticalcableaccidentallyseeswater,theentirelinkwillseepandbescrapped.Undernormalcircumstances,evenifthereisanaccidentalwaterseepage,youonlyneedtorepairthewaterseepage,andyoudon'tneedtodoitagain.(Thenationalstandardrequiresthatthewaterblockingperformanceis:threemetersofopticalcable,onemeterofwatercolumnpressure,nowaterseepagefor24hours.)Ifyouusepoorointment,theaboveproblemswillalsooccur,anditmaybeduetothepoorthixotropyoftheointment.,Theopticalfiberwillcausemicro-bendingloss,andthetransmissioncharacteristicsoftheentirelinkwillbeunqualified;ifthegreaseisacidic,itwillreactwiththemetalmaterialintheopticalcabletoprecipitatehydrogenmolecules,andtheattenuationoftheopticalfiberwillincreaserapidlywhenitencountersH,causingtheentireThelinkisinterruptedfortransmission.

Seven.Aramid:AlsoknownasKevlar,itisakindofhigh-strengthchemicalfiber,whichismostusedinthemilitaryindustry.Militaryhelmetsandbulletproofvestsareproducedfromthismaterial.Asof2013,onlyDuPontandtheDutchAkzocanproducethem,andthepriceisabout300,000tons.Indooropticalcablesandelectricaloverheadopticalcables(ADSS)bothusearamidyarnasreinforcements.Becausearamidcostsarehigh,inferiorindooropticalcablesgenerallyhaveaverythinouterdiameter,sothatafewstrandsofaramidcanbeusedtosavecosts.Suchanopticalcableiseasytobebrokenwhenpassingthroughthetube.BecauseADSSopticalcabledeterminestheamountofaramidfiberusedintheopticalcableaccordingtothespanandwindspeedpersecond,itisgenerallynotafraidtocutcorners.

8.Water-blockingtape:Thewater-blockingtapeoryarnforopticalcableshasstrongwater-absorbingperformancethroughtheuniformlydistributedsuperabsorbentresininsidetheproduct.Underthecombinedactionofrubberelasticity,superabsorbentresincanquicklyabsorbwaterseveraltimesitsownweight.Moreover,thewaterblockingpowderwillswellthegelimmediatelyonceitencounterswater,andnomatterhowmuchpressureisappliedtoit,thewaterwillnotbesqueezedout.Therefore,thecablecoreiscoveredwithawater-blockingtapecontainingwater-absorbentresin.Incasetheouterwalloftheopticalcableisdamaged,thesuperabsorbentresininthewoundpartwillswellandexertasealingeffect,whichcanpreventtheentryofwatertoaminimum.Inferiorfiberopticcablesusuallyusenon-wovenfabricsorpapertapes.Oncetheouterskinofthefiberopticcableisdamaged,theconsequenceswillbeveryserious.

Discusstheimportanceofcommunicationopticalcablelinemaintenanceandspecificcountermeasures

Theinformationageiscoming,andthedevelopmentofvariousindustriesinmycountrytodayiscloselyrelatedtocommunicationtechnology.Therefore,bothcompaniesandpeoplehavehigherrequirementsforcommunicationlevels,andthecommunicationindustryisdevelopingveryrapidly,buttherearestillmanyproblemsthathavenotbeenresolved.Thequalityofcommunicationtechnologyisdirectlyrelatedtothecurrentmaintenanceofcommunicationopticalcablelines.Thisarticleanalyzesthemeaningandspecificmethodsofcommunicationopticalcablelinemaintenanceforpracticalapplications.

Commoncausesofobstacles

FindingObstaclePoints

ThemethodstepsofusingOTDRtesttodeterminetheobstructionpointofopticalcablelineattheendpointorrelaystationareroughlyasfollows:

1)UseOTDRtotestthemaximumdistancefromtheobstaclepointtothetestend.

2)Whentheopticalcableisblockedduetonaturaldisastersorexternalinfluencessuchasexternalconstruction,findtheobstaclelocationprovidedbythemaintenancepersonnelaccordingtothepersonnel.Ifitisnottheabovesituation,itisnoteasyfortheinspectorstofindtheobstaclelocationfromtheabnormalroadsurface.Atthistime,itisnecessarytocheckwiththeoriginaltestdataaccordingtothedistancebetweentheobstaclepointmeasuredbytheOTDRandthetestendtofindoutwhichmark(orwhichtwojoints)theobstaclepointisbetween.Afterpassingthenecessaryconversion,Byaccuratelymeasuringthelengthofthegroundduringthisperiod,thespecificlocationoftheobstaclecanbedetermined.

3)Ifthefiberbreakageiscausedbythestructuraldefectoftheopticalcableortheagingoftheopticalfiber,itisdifficulttoaccuratelymeasurethebreakpointwithOTDR,andonlytheobstructivesectioncanbemeasured,thenasectionofopticalcableshouldbeusedinstead.

Methodstoimprovetheaccuracyoffiberopticcablelinefaultlocation

Firstofall,itisnecessarytounderstandhowthemeterisusedandhowtousethemetertohelpaccuratemeasurement.

1.SettheOTDRparameters.WhenusinganOTDRtest,youmustfirstsettheinstrumentparameters,themostimportantofwhichistosettherefractiveindexandtestwavelengthofthetestfiber.Onlybyaccuratelysettingthebasicparametersofthetestinstrumentcanconditionsbecreatedforaccuratetesting.

2.Usethemagnifyingfunctionofthemeter.UsethezoomfunctionofOTDRtoaccuratelyplacethecursoronthecorrespondinginflectionpoint,andusethezoomfunctionkeytozoominto25meters/div.Inthisway,moreaccuratetestresultswitharesolutionoflessthan1metercanbeobtained.

3.Adjusttheaccuratetestrangefile.Fordifferenttestrangefiles,thedistanceresolutionofOTDRtestisdifferent.Whenmeasuringopticalfiberobstaclepoints,youshouldselectthetestrangefilethatisgreaterthanthemeasureddistanceandtheclosest,sothattheaccuracyofthemetercanbefullyutilizedformeasurement.

Secondly,accurateandcompleteoriginaldocumentsshouldbeestablishedduringthemaintenanceandmanagementprocess.Theseaccuratelycompletedopticalcablelinefilesarethebasicbasisforfaultmeasurementandlocation.Therefore,intheprocessofmaintenanceandmanagement,weshouldnotbenegligent,andshouldestablishtrue,credibleandcompletelineinformation.

Whentheopticalcableconnectionismonitored,thecumulativelengthoftheopticalfiberfromthetestendtoeachjointpointandthetotalattenuationvalueoftheintermediatefiberarerecorded.Atthesametime,thetestinstrumentmodelandthesettingoftherefractiveindexduringthetestarealsorecorded.Thevalueisregistered.Accuratelyrecordtheremainingfiberopticcables.Recordindetailthelengthoftheopticalcablereelineachjointpit,specialsection,S-shapedlaying,roomentry,etc.andthelengthoftheopticalfiberreelinthejointbox,terminalbox,ODFrack,etc.,sothatitcanbedeductedwhenconvertingtheroutelengthofthefaultpoint.

Inaddition,theconsistencyofthetestconditionsshouldbemaintainedduringthemeasurementprocess.Duringtheobstacletest,trytoensuretheconsistencyofthetestinstrumentmodel,operationmethodandinstrumentparametersettings,etc.,sothatthetestresultsarecomparable.Therefore,eachtestinstrumentmodelandtestparametersettingsmustberecordedindetailforfutureuse.

Finally,acomprehensiveanalysis.Theobstacletestrequiresthattheoperatormusthaveaclearthinkingandaflexiblewaytodealwiththeproblem,andaclearlogicalthinkingisveryusefulwhereveritis.Undernormalcircumstances,two-wayfaulttestsareperformedonbothendsofthefiberopticcableline,andthencombinedwiththeoriginaldataforanalysis,andthenreadytodeterminethespecificlocationofthefault.Whenthelinkaroundthefaultpointhasnoobviouscharacteristicsandthespecificsitecannotbedetermined,thenwecantakethemeasurementmethodatthenearestjoint,whichcanexcavateattheobstaclepointofthepreliminarytest,andtheendstationtestinstrumentisinthereal-timemeasurementstate.

Restorationofobstacles

Iftheopticalcablelineisobstructed,everysecondmustbedetermined.Temporarilyadjustthecircuitorlaytheemergencyopticalcabletotemporarilyseizethecircuit,andorganizeforcestorepairitassoonaspossible.

1.Emergencyrepair

1)Allopticalcablelinesinonedirectionareblocked

Accordingtothescheduledcircuitschedulingplan,immediatelyTemporarilyadjustallcircuitsorpartofthemaincircuits.

2)Theindividualfiberoftheopticalcablelineinacertaindirectionisblocked

Ifthereisasparefiberintheopticalfiber,orthereisanothercircuitouscircuit,immediatelyusethesparefiberorcircuittotemporarilyadjusttheobstaclecircuit;Ifthereisasparefiberintheopticalcableandthereisnocircuitouscircuit,itshallbedealtwithaccordingtothestipulatedschedulingprincipletoensurethattheimportantcircuitisunblocked,andthesecondarycircuitissuspended.

3)Partoftheopticalfiberoftheopticalcablelineinacertaindirectionisblocked

Ifthereareopticalfibersintheopticalcable,inadditiontousingthespareopticalfibertotemporarilyadjustthecircuit,youcanselectanunblockedopticalfibertemporarilyPairing,inaccordancewiththeprescribedschedulingprincipleandschedulingsequence,temporarilyadjustthecircuit,ifthetemporarilypairedfiberisstillnotenough,andthereisnocircuitouscircuit,thenthesecondarycircuitissuspended.

Notes:

1.Thetemporarydispatchoftheaboveopticalfibermustbenegotiatedbybothsidesofthemachineandline.Completedinclosecooperation.

2.Fortheopticalfiberspairedintheoriginallinesequence,aslongasthetwoendsofthemaintenancestationaccordingtothesystemscheduling,switchthecircuit;iftheopticalfibersarepairedtemporarily,theopticaldistributionracksintherelaystationsonbothsidesoftheobstacleshouldbeused.(Orterminalbox)toadjusttheconnection.

3.Ifthemainopticalfiberisconnectedwithanopticalattenuator,butthespareopticalfiberisnotpre-connectedwithanattenuator,thecorrespondingopticalattenuatorshouldalsobeconnectedwhenthespareopticalfiberisused.Thisissueshouldalsobepaidattentiontowhenopticalfiberpairingisusedtemporarily.

2.Layingemergencyopticalcables

1)Conditionsforplacingemergencyopticalcables

WhentheopticalcablelinesinacertaindirectionareallblockedAfterallthecircuitsorthemaincircuitareswitchedon,youcanconsiderrepairingtheopticalcableatonetime,insteadofusinganemergencycircuit.Whenthereisnoconditiontotemporarilytunethecircuit,orthetemporarytunedpartofthecircuitcannotmeettheneedsoflarge-capacitycommunication,theemergencyopticalcableshouldbelaid,andthecircuitshouldberushedinaccordancewiththeschedulingprincipleandschedulingsequencestipulatedinthe"circuitschedulingsystem".Resumecommunication,andthenre-choosetheroutetolayoutnewopticalcablesforformalrestoration.

2)Determiningthedeploymentrangeofemergencyopticalcables

Opticalcablesareblockedbynaturaldisastersorexternalforces.Generally,afterdeterminingtheapproximatelocationoftheobstacles,itiseasiertofindthemaccordingtotheabnormalroadsurface.Obstaclepoints,thedeploymentrangeofemergencyopticalcablescanbedetermined.However,itisdifficulttodeterminethedeploymentrangeoftheemergencyopticalcablewhentheOTDRonlydetectstheobstaclepointattheendstationortherelaystation,whichisbetweenwhichtwojoints,andcannotdeterminethespecificlocationoftheobstacle.Atthistime,ifconditionspermit,youcanuseOTDRtotestattheremoterelaystation,andconductacomprehensiveanalysisofthetestresultsonbothsides.Generally,youcanaccuratelydeterminetheopticalcablebreakpoint.IfthereisnoconditiontouseOTDRtestfromtwodirections,youcansendtwoseparatelyTodealwiththissituation:

a)Theobstaclepointisrelativelyclosetoaconnector,andtheemergencyopticalcableistobelaidoutfromthisconnector.OpenthisconnectorandusetheOTDRtotestinthedirectionoftheobstacleattheconnector.Atthistime,testThedistanceisshort,thespecificlocationoftheobstaclecanbemeasuredmoreaccurately,andtheemergencyopticalcablecanbedeterminedwheretolay.

b)Theobstaclepointislocatedinthemiddleofthetwojoints.Itisnotadvisabletostartlayingtheemergencyopticalcablefromajoint.Itisnecessarytofurtherdeterminethepositionoftheobstaclepointandplaceanemergencysectiononbothsidesoftheobstaclepoint.Opticalcable.Inthiscase,youcanusethestep-by-stepextensionheuristicmethodtofindthespecificlocationoftheobstacle,thatis,usetheOTDRtoinitiallymeasuretheobstaclepointattheendstationortherelaystation,digouttheopticalcableinfrontoftheobstaclepoint,andcutacertainopticalfiberforre-testing,suchasIftheobstacleisnotinthecut-offrange,youshouldjudgetheapproximatedistance,thendigouttheopticalcableforward,cutoffanotheropticalfiberandre-test,untiltheobstacleiswithinthecut-offpoint,youcandeterminetheemergencyThedeploymentrangeoftheopticalcable.Generally,thespecificlocationoftheobstaclecanbedeterminedbyretestingtwice.

c)Thesametypeofopticalfibercabletoacceleratetheemergencyrepairoftheconnector

Anothertypeofopticalcableemergencyrepairmethodistousethesametypeofopticalcableastheobstacleopticalcableastheemergencyrepairopticalcable,usingtheconnector(Flexiblejoint)addmatchingliquidfortemporaryconnection,andrushthroughthecircuit.

3.Formalrepair

Whenformallyrepairingopticalcablelineobstacles,communicationmustbemaintainedasmuchaspossible,especiallythecommunicationofimportantcircuitsmustnotbeinterrupted,andtheconstructionqualitymustconformtotheopticalcableRequirementsforlineconstructionqualitystandardsandmaintenancequalitystandards.

Whenofficiallyrepairingthefull-blockingobstaclesoftheopticalcableline,thefollowingissuesshouldbepaidattentionto:

1.Fortheobstaclesintheconnectorboxorneartheconnector,theopticalfiberorconnectorpitreservedintheconnectorboxshouldbeusedtopreventLeavethefiberopticcableforrepair,noneedtoaddadditionalconnectors.Whenthereisareservedopticalcableneartheobstaclepoint,thereservedopticalcableshouldbeusedforconnection,andonlyoneconnectorshouldbeadded.

2.Whenitisnecessarytouseinterventionorreplacementoftheopticalcabletoformallyrepairtheopticalcableobstacle,thesamemanufacturerandthesametypeofopticalcableshouldbeused.

3.Thelengthoftheinterventionorreplacementoftheopticalcablecanbeconsideredbythefollowingthreefactors:

(1)ConsideringthattheendstationorrelaystationmustuseOTDRtomonitorwhentheopticalfiberconnectionisofficiallyrepaired,Oritisconvenienttodistinguishtheobstaclesbetweentwoadjacentconnectionpointsindailymaintenancework;theminimumlengthoftheinterventionorreplacementoftheopticalcablemustmeettheresponseresolution(two-pointresolution)requirementoftheOTDRinstrument,anditshouldgenerallybegreaterthan100meters.

(2)Consideringthatitdoesnotaffectthesingle-modefibertoworkunderasingle-modesteady-stateconditiontoensurecommunicationquality,theminimumlengthofinterventionorreplacementoftheopticalcableshouldbegreaterthan22meters.

(3)Tointerveneorchangethelengthoftheopticalcable,pleaserefertotheprinciplerequirementsof(1)and(2),combinedwiththeactualsituationandcomprehensivelyconsiderit,andgraspitflexibly.Forexample,ifthereisaconnectorneartheinterventionorreplacementoftheopticalcable,theopticalcableshouldbeextendedtothejointasmuchaspossible,andonlyoneconnectorshouldbeadded.

4.Interveneorreplacetheopticalcable,thegeneralsequenceofopticalfibercutover:

(1)Firstofall,itshouldbebasedontheschedulingprinciplesstipulatedinthe"circuitschedulingsystem"Thetwopartiesandthedispatchingsequencemachinewilljointlynegotiateanopticalfibercutoverplanandsubmitittothesuperiorauthorityforapproval.

(2)Thefibercutoverprocessshouldtrynottointerruptthecircuit(especiallyimportantcircuits).Tocutandconnecttheoriginalandnewlydeployedopticalfiberbytheemergencyopticalcable,thespareopticalcableshouldbeconnectedfirst,andthespareopticalfiberisusedasareplacementpair.Pairthetransfercircuit,orifthereisnospareopticalcableintheoriginalopticalcable,thesecondarycircuitshouldbesuspended,andtheopticalfiberofthesystemshouldbecutoverasareplacementpair,andthenaccordingtotheoriginalcutoversequence,cutoveronebyonetorestorethecircuit.