AW10724 REV 3 Fibre Cabling Advice
Contents
1. Coverage www cobham com wireless AW10724 R03 Page 21 of 24 Fibre Optic Cabling Advice Guide e COERENTA 4 3 Understanding Optical Time Domain Reflectometry The optical time domain reflectometer OTDR injects an optical pulse into one end of the fibre and analyses the returning backscattered and reflected signal An operator at one end of a fibre span can measure and localize attenuation event loss reflectance and ORL Laser Diodes Photodiode Detector A schematic diagram showing OTDR technology What Does an OTDR Measure An OTDR detects locates and measures events on fibre links requiring access to only one end of the fibre Attenuation also called fibre loss Expressed in dB or dB km attenuation represents the loss or the rate of loss between two points along the fibre span Event Loss The difference in the optical power level before and after an event expressed in dB Reflectance The ratio of reflected power to incident power of an event expressed as a negative dB value The higher the reflectance the more light reflected back the worse the connection D Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 22 of 24 COBHAM Fihra Ontic Cahlina Advie MDL e UDUC Cdl J CE ATU Net Ld FL ZT L Optical Return Loss ORL The ratio of the reflected power to the incident power from a fibre optic link or system2. Coverage www cobham com wireless AW10724 R03 Page 20 of 24 Fibre Optic Cabling Advice Guide L CIBLE MUTT 4 2 Fibre Testing OTDR Fibre testing must be carried out during the fibre installation and before repeater commissioning commences Perform an OTDR measurement on the optical links at 1310 1550nm in both directions All discrete events must meet the defined thresholds as stated in FO Specification document The OTDR traces must recorded in industry standard SOR format for all wavelengths and pulse widths and be available for each fibre link end to end and include fibre patches to the master site to the Remote site Some OTDR s have simplified the OTDR trace analysis using icon based mapping with PASS FAIL limits making analysis more efficient which Cobham Wireless advises its Customers to use 1310nm 3ns BSC 1 ALPHA BASE STATION gt B 1 Trace 200 aoe Goen aire BASE STATION gt B NM pare meena nee 08 02 2012 14 19 Sa Event d View 47 A 0 27 k Sc nm dB dB m e WK 1310 0 537 50 49 39 74 10 0 10 20 30 40 50 m Event Distance m Loss dB Reflect dB Section Att dB Sectionm T Loss dB BR 9 74 0 498 52 93 0 032 9 74 0 032 Distance m Fault Detected S 9 74 Bad or ae connector Advanced f SM OTDR amp 2 OEO OTDR au JSM OTDR 2 OEO OTDR Typical OTDR and Trace with a corresponding SmartLink Map De Connected Seamless Wireless Cobham Wireless
3. Zone D 130 t0 250 PSS aS Power Measurement 30 67 d m 1310 Bios Reading 123 Low Magnification High Magnification Typical Inspection Report Note All disconnected fibres or bulkhead must be capped when not in use g Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 19 of 24 Fibre Optic Cabling Advice Guide L SI Iert 4 Fibre Testing Loss The Fibre system can tolerate an optical insertion loss over the fibre of up to 10dBo The output of the RF fibre optic converters is 5dBmo 2dBmo Any measurement of the loss over the fibre should include the fibre patch cords to the master and remote units end to end Loss should be measured at 1310 1550nm test wavelengths in both directions 4 1 Optical Receive Levels The levels of the received optical signals are displayed on the RF Status page Com Ea Terp ERIS Pw MEREM Pw 2 MEE Pw 3 MAE Temp ES Temp E Temp E Temp ES Temp ES Temp ES Pilot Synth Plot Surgb SS Piot Synth ES Pilot Synth Pilot Syrth ES Pilot Synth Ss Combiner Attenuation Dua 3 0 we OMU Fiber Optic Unit Temperature Transmitter Receved level EELA Pilot Tone Gen Synth Received Pilot Tone Level EEPROM CRE Repeater ri dh JL e AN dp ar NM i e i I SS Es L JS 1 LE z Connected Seamless Wireless Cobham Wireless
4. Light Transmitted BACK REFLECTION INSERTION LOSS CORE CLADDING DIRTY CONNECTION IF Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 8 of 24 Fibre Optic Cabling Advice Guide Dirty Fibre Connection CLEAN FIBER PITS CHIPS DIRT CONTAMINATION OIL CLEANING FLUID RESIDUE SCRATCH Fibre Connection and Various Connector Endface Views An ideal Fibre endface should be free from defects or scratches as shown in the following Microscope View of Clean Connector Endfaces Q Connected Seamless Wireless Coverage bl WT VVI CICS HTI M WI CIC AW10724 R03 Page 9 of 24 Fibre Optic Cabling Advice Guide e CIETA 1 3 4 Fibre Connector Endface Inspection Zones and Grading Inspection zones are a series of concentric circles that identify areas of interest on the connector end face The inner most zones are more sensitive to contamination than the outer zones It is common to divide the image into a series of concentric circles that begin with a small one centred on the core also known as zone A and then radiate out from there This creates a bulls eye pattern sometimes called a grading overlay The overlay is used to GRADE the Fibre by determining the number and size of each particle that are present in each of the 4 Fibre zones A CORE ZONE B CLADDING ZONE C ADHESIVE EPOXY ZONE D CONTACT FERRULE ZONE UND P
5. 1 Select the appropriate cleaning tool for the connector type 2 Pull off the guide cap Dry Clean 3 Push into bulkhead 2 times 2 clicks Note for hard to reach places push the nozzle extender lock and pull the nozzle out Nozzle Extender Lock Inspect 4 Insert the FIT into the bulkhead to inspect 5 Determine whether it is CLEAN or DIRTY e IF CLEAN DO NOT TOUCH IT and CONNECT IF DIRTY either repeat the DRY cleaning or go to a wet dry cleaning process g Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 17 of 24 Fibre Optic Cabling Advice Guide L OCIESFMIFMUITT 3 4 Cleaning Process Before cleaning 1 Inspect the connector 2 If it is clean do not clean it connect it If it is dirty try a dry cleaning method 1 Use approved cleaner 2 Repeat 2 or 3 times if needed 3 If the debris remains it is bonded to the surface or mated in not removable 4 Inspect after each Cleaning attempt If after dry cleaning it is still dirty try a wet to dry cleaning method 1 Use approved solvent 2 Do not saturate the cloth or tape damp is effective soaking wet is not 3 Wet cleaning must be followed immediately by dry cleaning 4 Wet dry can be one step moving from damp to dry on a wipe or two steps damp wipe followed by dry wipe 5 Repeat 2 or 3 times if needed 6 If the debris remains it is mated in not removable 7 Insp
6. SINGLE MODE FIBER Fibre Endface Inspection Zones for Single Fibre Connection 1 4 Fibre Inspection Acceptance Criteria Acceptance Criteria are a series of failure thresholds that define defect limits for each zone on the Fibre connector endface All loose particles must be removed If defect s are non removable it must be within the criteria specified to be acceptable for use The tables below list the Acceptance Criteria standardized by the International Electrotechnical Commission IEC for single mode connectors as documented in IEC 61300 3 35 Ed 1 0 All Fibre connectors shall be inspected and a PASS Certification report produced to prove compliancy with these criteria before being activation of the Cobham Wireless Equipment SC Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 10 of 24 Fibre Optic Cabling Advice Guide e SI Iert Single Mode APC Zone Name Scratches Defects Diameter Core Zone 0 25um 4 lt 3pm one Cladding Zone 25 120um No limit No limit lt 2 um None gt 5 um 120 130um D Contact Zone 130 250um None gt 10 um e All loose particles must be removed If defect s are non removable it must be within the criteria above to be acceptable for use e For scratches the requirements refer to width e No visible surface cracks are allowed on the core or cladding zone e There are no requirements for the area outside the contact zone since
7. defects in this area have no influence on optical performance Cleaning loose debris beyond this section is recommended good practice e The limit for non linear non removable features in the ferrule contact zone D does not apply for metal alloy ferruled connectors like E2000 Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 11 of 24 Fibre Optic Cabling Advice Guide COBH 2 Fibre Connector Inspect Clean Connect Process Visual Inspection of Fibre interconnects is the only way to determine if connectors are clean prior to mating them A video microscope magnifies an image of a connector endface for viewing on either a laptop or portable display depending on the product used The requirement to inspect Fibre connectors and clean if necessary before connection is mandatory in all cases this includes the first use of new cords and transceivers or any equipment panels with Fibre interfaces Inspect Clean Connect Process Flow Ensure ESD control amp prevention techniques are followed Employ the inspect clean connect process as per the following diagram and steps INSPECT K INSPECT 1 Select the appropriate tip for the connector adaptor you are inspecting Refer to the relevant inspection microscope user manual 2 Inspect both connector endfaces patchcord bulkhead pluggable interface using the microscope IS IT CLEAN No Upon inspection if non linea
8. hands e Film residues condensed from vapours in the air e Powdery coatings left after water or other solvents evaporate away Particles trapped between fibres faces can e Scratch the glass surfaces e Cause an air gap or misalignment between cores degrading the optical signal Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 5 of 24 Fibre Optic Q 1 3 1 Good Fibre Connection There are 3 basic principles that are critical to achieving an efficient optic Fibre connection 1 Optimal Core Alignment 2 Physical Contact 3 Clean Connector Interface Today s connector design and production techniques have eliminated most of the challenges to achieving core alignment and physical contact What remains challenging is maintaining a clean connector interface Fibre Connection Key Terms amp Concepts Fibre connectors enable Fibre to Fibre mating by aligning the two optical Fibres Fibre connectors come in various types and have different characteristics for use in different applications The main components of a Fibre connector are detailed in the following PA FIBRE CORD CONNECTOR BOOT FERRULE BODY iz FIBR Connected Seamless Wireless LIA V i Ja e b La Cobham Wireless Coverage www cobham com wireless DA DI P Geh Fibre Optic Cabling Advice Guide L SI Iert gesiess ge Te Ge CORE _ CLA
9. measures to distance and displays it on the trace Entering the appropriate value for the fibre under test will ensure accurate measurements of fibre length Range This relates to the distance of the fibre under test Most modern OTDR have automatic length detection If fibre under test distance is know it should be inserted Range should be set to 1 5 2 times the distance of the fibre Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless DA VIN d ua ALATA NIAAA M AVV 24 R 5 Fibre Optic Cabling Advice Guide L COES Note To obtain accurate measurements always ensure to use a long launch lead and inspect and clean all connectors prior to OTDR testing Some OTDRS are capable of automatic Bi directional OTDR and IL measurements 0 Pot Batch Panels Fibre Infrastructure bt dam carti Parameter Alarms Values Splice Loss Typ 0 25dB Typ 0 5dB Connector Reflectance lt 60dB Link Loss between OMU and repeater lt 10dB including connection patch cords Note While splice and connector loss are recommendation alarm thresholds overall insertion loss and connector reflectance is a mandatory critical parameter threshold to meet system requirements Having low loss connections will help improve optical performance and minimize reflections g Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 24 of 24
10. return loss characteristics For inspection of APC connectors an APC microscope tip is required to achieve incident angles suitable for image illumination and viewing hay 8 ee With Angled Physical Contact APC finishes a ia i the connector tip is cut to 8 degrees which my L directs the reflected light away from the source 60 dB Upto0 00032 Back Reflection SC UPC SC UPC is the wrong connector type it is generally identified by a blue connector boot and uses Physical Contact PC 0 WARNING This type of connector must not be used anywhere within the repeater fibre network the Insertion loss reflectance is too high and will disrupt the communications between nodes preventing the system from being commissioned UPC Ultra Polish Connector Uoto 0 001 Back Reflection seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 4 of 24 Fibre Optic Cabling Advice Guide COBH 1 3 Avoiding Fibre Contamination Contamination ts the 1 source of troubleshooting in optical networks A single particle mated into the core of a Fibre can cause significant back reflection also Known as Return Loss insertion loss and can damage equipment Visual inspection is the only way to determine if Fibre connectors are truly clean before mating them Cobham Wireless advises 100 visual inspection is carried out on all interfaces By implementing a simple yet important process o
11. CEIVE LGVEIS ce siusasayacansactinatapnocadenseaanas a nies aia TAa ni me Aaii 20 4 2 PDE FSS CE OTOR aa A A A A A A A 21 4 3 Understanding Optical Time Domain Reflectometry uk 22 4 3 2 How to Configure the Main OTDR Settings cscscsscscsnesececsecesseceseeensneareneateneseoasseonseeansenansneatsneatsnsgs 23 Cobham Wireless Coverage ALAJ ATADA a EA e WAAT NZ Tel LI FAV V U J ainT U D Connected Seamless Wireless www cobham com wireless 24 Ca D SAA D Al radc UI 4 COBHAM Introduction The purpose of this document is to advise on the correct method of Installing and testing a fibre network The importance of why this advice should be followed is that failure to complete the points within this advice guide correctly will lead to a increased time b increased cost c poor performance of the communications between equipment OMU to remote units Cobham Wireless advises that only End to End Fibre testing is carried out Do not just test the core Fibre cable as this is a waste of time and all patch cables pig tails jumper cables need to be testing as part of the entire End to End Fibre link 1 Fibre It is important to make measurements to ensure a correct installation of the fibre distribution system prior to Installation of any fibre equipment When the fibre cable has been installed the quality of the optical path should be checked for optical path loss over the entire length en
12. DDING Fibre Connector Components LCPC Example Body Houses the ferrule that secures the Fibre in place utilizes a latch and key mechanism that aligns the Fibre and prevents the rotation of ferrules of two mated connectors Ferrule Thin cylinder where the Fibre is mounted and acts as the Fibre alignment mechanism the end of the Fibre is located at the end of the ferrule which is referred to as the endface throughout this document The overall diameter of the ferrule depends on the relevant connector type There are typically two ferrules diameters used 2 5 mm dia e g SC APC type connectors and the smaller 1 25 mm dia e g LCPC type connectors Fibre CLADDING Glass layer surrounding the core which prevents the signal in the core from escaping 125 um dia for single connectors CORE The critical centre layer of the Fibre the conduit that light passes through 8 10 um dia for single mode connectors Angled PC Pre installed Fiber Inserting Fiber Matching Oil Fibre Connection SC APC Through Connect Example C7 e A Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 7 of 24 Fibre Optic Cabling Advice Guide L COERENTA 1 3 2 Fibre Connector Endface defects There are many types of defects Commonly used terminologies include contamination particles pits chips scratches loose contamination and embedded contamination etc For this docume
13. Fibre Cabling Installation and Inspection Advice Guide The most important thing we build is trust Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 RO3 ji COBHAM Fibre Optic Cabling Advice Guide Table of Contents 1 leie 3 i es A Fre Ralete ge 3 1 2 Differences in lege ein e ge EE d 1 3 Avoiding Fibre Contamination E 5 ie Sab Good FID C C Ol MOGE e EE 6 1 3 2 Fibre Connector Endface defects EE 8 US 2 Scratches and Non linear features xs kEKN KEN KENNEN ENKNKNERN KEN KKK KKK KRRK NK NR REN K ENKEN REN EKRK RER KEN R ENN KKK KRNK 8 1 3 4 Fibre Connector Endface Inspection Zones ANd Gradimg EE 10 1 4 Fibre Inspection Acceptance Criterta EEN 10 2 Fibre Connector Inspect Clean Connect Process NNN NNN NNN 12 sch Optical Fibre Interface Inepechon xexkNk NENNEN RER RER ENNEN ENNER REENEN RER NENNEN RENE NR ENNEN NENNEN 13 2 Mets PACHECO ie e gel BEE 13 2 1 2 Bulkhead Through Adaptor Connector Inspechon ENEE 13 3 Optical Fibre Connector Cleaning Process cscsccsececsearsnearcnenecesseceseeansnearsnestsaseeoaseeanseeansneatsnsaesaseness 14 eck Optical Fibre patchcord Cleaning EE 14 3 2 P ALCON GI CANA anaa 16 3 3 BUIKMEAG e lune sssini arna E aAa Eaa a ERER iina 16 3 3 1 Bulkhead Through Adaptor Connector Cleaning Tools 16 3 4 e Unter 18 3 5 Fibre Connector Inspection IEC Certification Reporting ENEE 19 d liewe AR 20 4 1 Optical RE
14. aning Cleaning fluids or solvents are generally used in combination with wipes in order to provide a combination of chemical and mechanical action to clean the Fibre endface Also available are pre soaked wipes supplied in sealed sachets e g IPA Medi swabs Some cleaning fluids particularly IPA can leave a residue which can be difficult to remove Cleaning fluid is only effective when used with mechanical action provided by a wipe The solvent type must be fast drying Follow safe handling procedures Do not over saturate as this will over wet the endface Only lightly moisten the wipe The ferrule must be cleaned immediately with a clean dry wipe Do not to leave solvent on the side walls of the ferrule as this will transfer onto the optical alignment sleeve during connection Wipes must be used in the hand or on a soft surface or resilient pad e Use on a hard surface can cause damage to the Fibre Examples of Cleaning Fluid and Wipes O Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 15 of 24 3 2 Patchcord Cleaning Patchcord or Pigtail Cleaning Process What Action 1 Select the IBC tool for the connector type 2 Pull off the guide cap cover Dry Clean 3 Attach the IBC to the connector and push into patchcord 2 times 2 clicks Inspect 4 Attach the patchcord to the FIT 5 Determine whether it is CLEAN or Dirty e IF CLEAN DO NOT TOUCH IT a
15. d to end and the magnitude and location of any reflections All fibre connectors should be certified to meet industry standards see FO Specification document Cobham Wireless requires Optical Time Domain Reflectometer OTDR measurement Optical reflections can degrade the linearity of a fibre optic link and introduce noise hence why it is important to confirm your fibre is working within tolerance Keep all discrete reflections to gt 60 dB The SC APC connectors specified are polished to a return loss gt 60 dB 1 1 Fibre Connectors e All fibres must be terminated with SC APC Angled Physical Contact these with tuned 8 connectors IEC 60874 14 9 must be used throughout the whole link between the master unit and the repeater e The fibre must be Single Mono mode fibre to ITU T Recommendation G 652 e SC APC connectors complying to endface conditions equal to IEC 61300 3 35 must be used on any ODF connections Patch Remote Site Panels Fibre Infrastructure Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless Fibre Optic Cabling Advice Guide COBH 1 2 Differences in Fibre connectors SC APC SC APC is the correct connector type and can be identified by a green connector boot and a square section The fibre end is Angle Polished APC 8 this offers a large surface area of contact between both fibres APC improve coupling efficiency and minimize connector back reflection or
16. ect after each Cleaning attempt If the debris remains non removable 1 Inspect the connector 2 Select the appropriate profile and test the connector end face in compliance to the pre configured Telecom acceptance criteria using FibreChek2 i e SM In service IEC 61300 3 35 Table 3 setting a If it passes make the final connection b If it fails can the connector be replaced If so then replace the connector c A failure report as shown on the following page must be generated d Failure Report to be submitted to your company Quality Assurance Auditor Manager for submission to QA Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless ALAJA A ANA W TA H II LA A Ia dE 1 O UI 24 Fibre Optic Cabling Advice Guide L COES 3 5 Fibre Connector Inspection IEC Certification Reporting It is a mandatory requirement that PASS FAIL certified inspection reports of each Fibre connector in a cable plant is provided during link Construction and installation The inspection IEC certified PASS FAIL report provides an archive summary of the final quality of the endface during connector installation acceptance FiberChek Fibre Inspection Inspection Date 08 06 2012 13 26 35 Company Name Fiber TestCo Location 3545 Cell Site X Operator John Smith Inspection Summary Profile Name SM APC IEC 61300 3 35 Ze L Zonea 0t EC Zone B 25to12y PASS Zone 120to130 PASS ASS
17. ed e Cleaning against a hard surface can damage the connector Designed for optics cleaning tools will have a firm yet yielding backing e Use solvents only after attempting a dry cleaning method Most cleaning solvents including IPA will leave an unacceptable residue if not applied and used correctly use a designed for optics solvent or IPA e g 70 IPA Medi swab e Do not saturate the optical interface with solvent Always follow solvent application with a dry cleaning process e Cleaning machines that use solvent without mechanical action may be exempt from the above cautions regarding over use of solvents e Inspect before you connect Every time This is the only way to ensure that interconnecting optic Fibre interfaces are acceptable for use 3 1 Optical Fibre patchcord Cleaning Cleaning Wipes and Tools Dry Cleaning Simple dry cleaning wipes including many types of lint free wipes and other purpose built wipes are available This category also includes purpose built optic Fibre connector cleaning cassettes and reels e g Cletop cartridges Warning Exposed wipes can easily become cross contaminated in the field Cleaning material must be protected from contamination until just prior to use Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AYA a rs a A ge P CG e AAT 7 DA BDB DS e en s di D A AVV U Z4 KUS rale Te CH d Fibre Optic Cabling Advice Guide L CE HETA Damp Cle
18. expressed as a positive dB value Measure of the amount of light that is reflected back from a feature forward power to the reflected power The bigger the number in dBs the less light is being reflected The OTDR is able to measure not only the total ORL of the link but also section ORL 4 3 2 How to Configure the Main OTDR Settings Pulse Width and deadzones The pulse width controls the amount of light injected into a fibre A short pulse width enables high resolution and short dead zones but less dynamic range A long pulse width enables high dynamic range but less resolution and large dead zones H H Attenuation Dead Zone ADZ is the minimum distance after a reflective event that CG a non reflective event can be measured 0 5dB H e In this case the two events are more closely spaced than the ADZ and shown as D one event i e ADZ can be reduced using shorter pulse widths Event Dead Zone EDZ is the minimum distance where 2 consecutive unsaturated reflective events can be distinguished e In this case the two events are more closely spaced than the EDZ and shown as one event e EDZ can be reduced using shorter pulse widths Acquisition Time Averaging The time during which the OTDR acquires and averages data points from the fibre under test Increasing the acquisition time improves the dynamic range without affecting resolution or dead zones Index of Refraction oh The IoR converts the time that the OTDR
19. f proactive visual inspection and cleaning poor optical signal performance and potential equipment damage can be avoided INSPECT KS IS IT CLEAN YES NO ia oN CONNECT Optical Connector Inspect Clean Connect Process Clean optic Fibre components are imperative to the quality of optical performance within any optic Fibre link It is the most basic and important procedure which has to carried out before mating together any optic Fibre assembly Any contamination in the Fibre connection can cause failure of that component and even failure of the whole system Hence clean components are a necessity for quality connections with optic Fibres When cleaning Fibre components the procedure must be followed correctly precisely and carefully with the goal of eliminating any dust or contamination A clean component will connect properly a dirty component may transfer contamination to the mating connector or it may even damage the optical contacts Remember components are not guaranteed to be clean on receipt from the supplier A particle that partially or completely blocks the core will generate strong back reflections which may make a laser system unstable It is essential that all optics are cleaned and inspected A 1 micrometer dust particle on a single mode core can block up to 1 of the light a 0 05dB loss A 9 micrometer speck can completely block the fibre core Other contamination e Oils frequently from human
20. nd CONNECT IF DIRTY either repeat the DRY cleaning or go to a wet dry cleaning process 3 3 Bulkhead Cleaning Common methods for cleaning optic Fibre endfaces that remain within an alignment sleeve bulkhead through adaptor transceiver or other receptacle type device 3 3 1 Bulkhead Through Adaptor Connector Cleaning Tools In adaptor or in situ connectors are most typically a connector that cannot be readily removed from a bulkhead through adaptor and are therefore more difficult to access This category includes ferrule interface or Fibre stubs and physical contact lens within an optical transceiver but does not include non contact lens elements within such devices Sticks and bulkhead cleaners are designed to reach into alignment sleeves and other cavities to reach the endface lens and aid in removal of debris i e moveable non linear features These tools allow the cleaning of the endface lens within the adaptor or in situ without the removal of the bulkhead connector When cleaning transceiver or receptacles care must be taken to carefully identify what is within the port prior to cleaning Caution must be taken when cleaning transceiver flat lenses due to possible damage Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 16 of 24 Fibre Optic Cabling Advice Guide e COES Bulkhead Through Adaptor Cleaning Tools Bulkhead Cleaning Process What Action
21. nt the defects will form two categories 1 Scratches Permanent linear surface features 2 Non linear Features Visible detectable on the Fibre endface These include contamination particles debris pits chips etc 1 3 3 Scratches and Non linear features Scratches are typically created during incorrect cleaning practices or mishandling of Fibre connectors Scratches near and or across the core are problematic because they create back reflection Dirt is everywhere a typical dust particle 2 15um in diameter can significantly affect signal performance and cause permanent damage to the Fibre endface Most field test failures can be attributed to dirty connectors and most of them are not inspected until the problem is detected after permanent damage has already occurred If dirt particles get on the core surface the light becomes blocked creating unacceptable insertion loss and back reflection return loss Furthermore those particles can permanently damage the glass interface digging into the glass and leaving pits that create further back reflection if mated Also large particles of dirt on the cladding layer and or the ferrule can introduce a barrier that prevents physical contact and creates an air gap between the Fibres To further complicate matters loose particles have a tendency to migrate into the air gap Light Transmitted CLADDING CORE CLEAN CONNECTION Clean Fibre Connection Minimum Insertion and Return Loss
22. pection and fit it to the probe microscope 2 Insert the probe into the bulkhead and adjust focus to inspect 4 FERRULE KE LG SINGLE MODE FIBER A a Bulkhead Through Adaptor Connector Microscope Inspection Q Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 13 of 24 COBHAM Fihra Ontic Cahlina Advie MDL e UDUC Cdl J CE ATU Net Ld FL ZT L 3 Optical Fibre Connector Cleaning Process This section details the cleanliness requirements used to maintain consistent product quality and performance from manufacturer to installer This section describes conventional cleaning methods for optical interconnects Conventional cleaning may be used for any fixed optical interface such as optical connectors where it is possible to touch the surface with the cleaning material Conventional cleaning is ineffective on non contact lens interfaces which are common on optical transceivers General optical interface cleaning principles e Optical components e g connectors transceivers must be clean to work optimally or in some cases at all e Use connector end caps They prevent damage however do not ensure cleanliness e Foam and cotton materials are not suitable for cleaning optics they can break down and deposit debris on the optical end face e Compressed air is ineffective in cleaning optical connectors or transceivers and must not be us
23. r features are visible on the CLEAN endface clean using an approved cleaning tool then re inspect Note 1 See cleaning section 9 CONNECT Yes If non removable non linear features and scratches are within acceptance criteria limits Note 1 Cleaning procedures may be applied up to five 5 times employing dry then damp cleaning processes Connected Seamless Wireless Cobham Wireless Coverage www cobham com wireless AW10724 R03 Page 12 of 24 Fibre Optic Cabling Advice Guide L CE HETA 2 1 Optical Fibre Interface Inspection Fibre endface inspections are performed through two different methods If the cable assembly is accessible you can insert the connector ferrule into the microscope to do an inspection this is generally known as patchcord inspection If the connector is within a mating adaptor on the device or patch panel you can use a probe microscope to insert into the open end of the adaptor and view the connector inside this is known as bulkhead or through adaptor connector inspection 2 1 1 Patchcord Inspection 1 Select the appropriate tip that corresponds to the connector type under inspection and fit it on to the microscope 2 Insert the connector into the tip and adjust focus to inspect 4 s F SINGLE MODE FIBER Patchcord Microscope Inspection 2 1 2 _Bulkhead Through Adaptor Connector Inspection 1 Select the appropriate tip probe that corresponds to the connector type under ins
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