1、ASD Technical Report Rapport Technique ASD ASD Fachbericht TR 4646 Edition 1 December 2008 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATIONAvenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 763 3565 - www.asd-stan.orgICS: Descripto
2、rs: ENGLISH VERSION Aerospace series Termination procedure for EN 4531 optical contact Srie arospatiale Procdure de cblage pour contact optique EN 4531 Luft- und Raumfahrt Montageanleitung, fr Kontakte nach EN 4531 This Technical Report was drawn up by the Electrical Domain of ASD-STAN. The reason w
3、hich led to the publication of the document as a Technical Report is explained in the foreword. Edition approved for publication 31 December 2008 Electrical Domain Copyright 2008 by ASD-STAN Page 2 TR 4646:12-08 Contents Page Foreword2 1 EN 4531-101 contact terminus assembly 3 2 Normative references
4、 3 3 Safety summary .3 4 Cable and fibre preparation3 5 Installation of the EN 4531 contact onto the fibre6 6 Fibre cleave . 11 7 Fibre end polishing. 11 7.1 General definitions before starting. 11 7.2 Coarse polishing. 13 7.3 Fine polishing AUTOMATIC. 13 7.4 Quality check. 13 8 Installation of the
5、terminus into a circular connector. 16 9 Insertion of the EN 4531-101 contact terminus into a rectangular ARINC style connector. 18 Foreword The main task of ASD-STAN Technical Committees is to prepare EN Standards, in exceptional circumstances however, the publication of Technical Report of one of
6、the following types may be proposed: Type 1, the subject is still under technical development requiring wider exposure; Type 2, a Technical Committee has collected data of a different kind from that which is normally published as a European Standard. The Electrical Domain decided to publish this doc
7、ument in the form of a Technical Report of type 2 in order to facilitate the updating of this document. Page 3 TR 4646:12-08 1 EN 4531-101 contact terminus assembly This termination process defines the stages to reach the minimum qualification requirements for the EN 4531 contact in accordance with
8、EN 4531-001. Other processes could be applied if they conform to the minimum qualification requirements and with common agreement between manufacturer and user. This standard aims at cable termination within manufacturing facility. CAUTION Training and qualification of personnel terminating fibre op
9、tic contacts is mandatory. Throughout the termination process, cleanliness is critical to obtain high optical quality termination. Ensure that work areas are kept as clean as possible to minimize the ingress of dirt into the connector parts. NOTE Verify that the epoxy adhesive shelf life has not exp
10、ired. Do not use epoxy adhesive with an expiration date that has passed. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the reference
11、d document (including any amendments) applies. EN 4531-001, Aerospace series Connectors, optical, circular, single and multipin, coupled by threaded ring Flush contacts Part 001: Technical specification. EN 4531-101, Aerospace series Connectors, optical, circular, single and multipin, coupled by thr
12、eaded ring Flush contacts Part 101: Optical contact for EN 4641-100 cable 55 C to 125 C Product standard. 3 Safety summary The following safety precautions shall be observed: a) Safety glasses shall be worn at all times when handling bare fibres or dispensing epoxy adhesive. b) To reduce the chance
13、of skin contamination wear suitable disposable gloves i.e. surgical latex gloves. c) Do not touch the ends of the fibre as they may puncture the skin. Wash the hands after handling bare fibre. d) Avoid skin contact with epoxy adhesives. e) Never look directly into the end of a fibre. Before inspecti
14、ng the end face of a fibre, verify that the fibre is not emitting energy or use a microscope with integrated camera. 4 Cable and fibre preparation Step 1 Before termination, clean minimum of 10 cm of the outer jacket of the cable end with a suitable optical quality cleaning solution (for example Iso
15、propyl Alcohol (IPA) impregnated wipes, or a lint free cloth dampened with the cleaning solution). Page 4 TR 4646:12-08 Cut the cable at an angle to facilitate the installation of the boot, see Figure 1. No strength member should protrude from the cable end. Figure 1 Cut cable at an angle Step 2 Ins
16、tall the cable marker sleeve and the supplied crimp sleeve, over the simplex cable (single fibre cable). Slide the cable marker sleeve, strain relief boot and the spring back from the end of the simplex cable. See Figure 2. Key 1 Wire marker sleeve 2 Simplex cable 3 Spring 4 Strain relief boot Figur
17、e 2 Installing cable marker sleeve, strain relief boot and spring 2 FO 123 (Tx) DDFR 1 4 3Page 5 TR 4646:12-08 Step 3 Mark the simplex cable outer jacket to 20 mm and to 25 mm, mark the cable as shown in Figure 3 below. Dimensions in millimetres Key 1 Mark 2 Optical fibre 3 Buffer 4 Aramid yarn 5 Ca
18、ble jacket Figure 3 EN 4531-101 contact cable stripping dimensions Step 4 Remove the simplex cable jackets back to 20 mm using the simplex cable stripper and trim the aramid yarn using the strength member shears so that only 1 mm is left from the jacket. NOTE The optimum way to remove the simplex ca
19、ble jackets is to ring cut the jacket with the simplex cable stripper and pull the jacket off by hand. Pushing off the simplex cable jacket with a tightly held simplex cable stripper can lead to fibre breakage. WARNING Wear safety glasses when removing the fibre buffer and coating to avoid possible
20、eye injury. Step 5 Mark the buffer at 17 mm. Remove the fibre buffer and coatings back to 17 mm using the buffer stripper. Remove the buffer and coating in small sections approximately 6 mm at a time. NOTE Normally, the buffer and coating are tightly adhered to one another and come off of the fibre
21、at the same time. CAUTION The uncoated fibre is in its most vulnerable state. Take extreme care not to damage the fibre. Breakage of any one fibre from this point until the connector is completely assembled will require repetition of this and the following steps in order to maintain approximately eq
22、ual length of all the fibres in the cable. 3+ 0 1 2 45 1 17 192083+ 0 1 Page 6 TR 4646:12-08 Step 6 Remove any residual coating material from the bare fibres with a wipe dampened with a quality optical cleaning solution. Wipe only once from the end of the buffer towards the end of the fibre. NOTE 1
23、Do not repeatedly wipe the bare fibre, as this will weaken the fibre. NOTE 2 Silicone coated fibres may require additional cleaning to ensure all of the silicone coating has been removed to ensure proper adhesion within the contact ferrule. 5 Installation of the EN 4531 contact onto the fibre NOTE 1
24、 This procedure describes the process for installing EN 4531 contact onto multimode fibres. Epoxy adhesive is used to secure the fibre in the contact for mating purposes. The manufacturers cure schedules should be closely followed for maximisation of the polymerisation process. NOTE 2 Step 1 below n
25、eeds to be accomplished prior to installing the contact onto the simplex cable. Step 1 Pre-heat a suitable curing oven to the required temperature, monitor the temperature using a thermometer or monitor the integrated temperature gauge. For the cure schedule, the following cure parameters should be
26、applied: Use of Epotek 353ND First polymerization at 90 C for 30 minutes, final polymerization at 125 C for 30 minutes. Use of Aremco 526N black First polymerization at 80 C for 2 hours, final polymerization at 165 C for 4 hours. Figure 4 Examples of epoxy curing oven Page 7 TR 4646:12-08 Step 2 Pre
27、pare the approved epoxy adhesive as detailed in the manufacturers instructions. CAUTION NOTE When using a 2 component epoxy adhesive, slowly mix the two parts together to minimise the introduction of air bubbles until the epoxy adhesive is smooth and uniform. Air bubbles in the epoxy adhesive can le
28、ad to connector failure during temperature extremes. Step 3 Remove the syringe plunger and pour the prepared epoxy adhesive into the syringe body, carefully re-insert the plunger. Allow the syringe to stand vertical until all air bubbles have risen to the surface. WARNING Wear safety glasses while d
29、ispensing the epoxy to avoid possible eye injury. Take care not to be injured during the syringe needle use. Step 4 Install the needle onto the syringe and remove excess air pockets in the syringe by holding the tip of the syringe upward and slowly depressing the plunger until the epoxy adhesive run
30、s free and clear from the tip of the syringe needle. Step 5 Inspect the contact and verify that the ferrule hole is free and clean of dirt. This can be accomplished by holding the front of the contact up to a light and verifying that the light is visible from the rear of the contact. If light cannot
31、 be seen through the contact, carefully push a piece of suitable sized piano wire through the contact hole to clear it. Then blow dry air through the hole to remove any debris. Step 6 Clean with alcohol the ferrule end, to ensure epoxy adhesion on this area. Step 7 Slide the contact, rear first, ont
32、o the syringe tip until it bottoms out inside the contact. Keeping the syringe vertical, depress the plunger and slowly inject epoxy adhesive into the terminus until a bead of epoxy can be seen on the ferrule end face. See Figure 5. Page 8 TR 4646:12-08 Key 1 Contact 2 Syringe filled with epoxy adhe
33、sive Figure 5 Injecting epoxy adhesive into the rear of the EN 4531 contact terminus Step 8 Wipe the syringe tip clean using a dry lint free wipe. Step 9 Install the contact onto the fibre by gently working the fibre through the contact until the cable marking is exactly located at the rear of the f
34、lange. Protrusion of the fibre shall be 4 mm minimum. See Figures 6 and 7. Key 1 4 mm minimum 2 Bead of epoxy adhesive 3 Marking Figure 6 Mounted contact scheme NOTE The outer cable jacket should come up to within 1 mm of the rear of the contact and the aramid yarn should be up inside the rear of th
35、e contact. 121 2 3Page 9 TR 4646:12-08 Key 1 Outer cable jacket 2 Contact Figure 7 Installing the contact onto the fibre Step 10 Verify that there is a small amount of epoxy adhesive around the fibre where it protrudes from the ferrule. If it is found that there is no small bead of epoxy adhesive on
36、 the contact tip, carefully add a small amount of epoxy around the fibre. See Figure 8. NOTE There should only be a small amount of epoxy adhesive around the fibre to support it during the polishing process. Key 1 Small bead of epoxy Figure 8 Bead of epoxy Step 11 Using a cleaning wipe, carefully wi
37、pe away any epoxy adhesive excess on the fibre that is more than 2 mm (0.1 in) from the ferrule tip surface. CAUTION Do not get epoxy adhesive on the outside of the ceramic ferrule of the contact. Wipe off any epoxy adhesive excess on the outside of the ceramic ferrule using a lint free cloth. Step
38、12 Insert contact into the cure adapter until it rests against the section, behind the ceramic ferrule. See Figure 9. 2 1 1 Page 10 TR 4646:12-08 Key 1 Terminus 2 Cure adapter Figure 9 Inserting the terminus into a cure adapter Step 13 Repeat steps 5 through 12 for each fibre to be terminated. Step
39、14 Ensure the oven temperature corresponds to the need. Step 15 Carefully place the contact in the curing oven, and position the cable vertically over the oven. NOTE 1 When the cable is positioned above the contact, make sure that no bends are introduced into the simplex cables. NOTE 2 Support clamp
40、 must be designed to ensure vertical position of the contact into the oven. Key 1 Terminus 2 Cure adapter Figure 10 Curing oven 1 21 2 Page 11 TR 4646:12-08 Step 16 After completion of the cure schedule remove the contact from the curing oven, and allow to cool down. WARNING Do not touch the contact
41、 when removing from the oven as severe burns will be the result. 6 Fibre cleave Step 1 After the contact has cooled down, carefully score the fibre close to the contact tip at the epoxy adhesive interface using one short light stroke with cleaving tool. See Figure 11. Pull off each fibre with a gent
42、le, straight pull. Deposit the waste fibre in a dedicated sharps container. NOTE Protrusion of the fibre shall be 4 mm minimum. If it is not the case, the cable has moved during the curing. The contact must be removed and replaced. Key 1 Fibre epoxy bead 2 Scribe tool 3 Contact Figure 11 Scoring the
43、 fibre 7 Fibre end polishing NOTE Automatic polishing process is more reliable and gives better optical results and repeatable end face profiling. WARNING Safety glasses should be worn prior to scribing the optical fibre. 7.1 General definitions before starting NOTE “Place the polishing paper on the
44、 support*” means: Step 1 Clean the support with a wipe dampened with alcohol or quality optical cleaning solution. 4 mm min. 1 23Page 12 TR 4646:12-08 Step 2 Clean the back of the polishing paper. Step 3 Place the polishing paper on the support. NOTE “Polish the ferrule*” means: Step 1 Clean the pol
45、ishing paper with a wipe dampened with alcohol or quality optical cleaning solution. Step 2 Clean polishing tool. Step 3 Put metallic polishing tool on paper surface. Step 4 Insert the terminus into the polishing tool (See Figure 12). NOTE 1 Difficulty in inserting the connector ferrule into the pol
46、ishing tool may indicate epoxy adhesive on outside of the ferrule that must be removed before proceeding. NOTE 2 Clean the terminus and polishing tool prior to terminus insertion. Key 1 Terminus 2 Polishing puck Figure 12 Inserting the terminus into the polishing tool 12Page 13 TR 4646:12-08 Step 5
47、Move the polishing tool applying very light pressure (the weight of the tool) using a Figure-8 motion, in order to well polish all the contact sides. NOTE Regularly clean the paper surface as previously explained in order to remove dust generated by the polishing process. 7.2 Coarse polishing Step 1
48、 Place the 9 m polishing paper on the Plexiglas support*. Step 2 Take the contact with your fingers as if you were writing with a pen. Start polishing manually without applying pressure on the contact. The objective is to polish away the fibre which projects beyond the epoxy adhesive surface. By doi
49、ng this, you prevent to scratch polishing paper while polishing (in future polishing steps). Stop this operation as soon as the excess fibre is has been removed. Step 3 Manually “Polish the ferrule*” and stop when all the epoxy adhesive is removed from the ferrule. NOTE Since polishing time varies with the amount of epoxy adhesive present on the ferrule end face, inspect the contact tip frequently. Whenever the polishing tool is lifted,
