EN 4533-001:2020
(Main)Aerospace series - Fibre optic systems - Handbook - Part 001: Termination methods and tools
Aerospace series - Fibre optic systems - Handbook - Part 001: Termination methods and tools
1.1 General
Part 001 of EN 4533 examines the termination of optical fibre cables used in aerospace applications. Termination is the act of installing an optical terminus onto the end of a buffered fibre or fibre optic cable. It encompasses several sequential procedures or practices. Although termini will have specific termination procedures, many share common elements and these are discussed in this document. Termination is required to form an optical link between any two network or system components or to join fibre optic links together.
The fibre optic terminus features a precision ferrule with a tight tolerance central bore hole to accommodate the optical fibre (suitably bonded in place and highly polished). Accurate alignment with another (mating) terminus will be provided within the interconnect (or connector) alignment mechanism. As well as single fibre ferrules, it is noted that multi-fibre ferrules exist (e.g. the MT ferrule) and these will also be discussed in this part of the handbook.
Another technology used to connect 2 fibres is the expanded beam. 2 ball lenses are used to expand, collimate and then refocus the light from and to fibres. Contacts are not mated together. It helps reducing the wear between 2 contacts and allows more mating cycles. This technology is less sensitive to misalignments and dust. Losses are remaining more stable than butt joint contact even if the nominal loss is higher.
A Note on Terminology
Current terminology in the aerospace fibre optics community refers to an optical terminus or termini. The term optical contact may be seen in some documents and has a similar meaning. However, the term contact is now generally reserved for electrical interconnection pins. The optical terminus (or termini) is housed within an interconnect (connector is an equivalent term). Interconnects can be single-way or multi-way. The interconnect or connector will generally house the alignment mechanism for the optical termini (usually a precision split-C sleeve made of ceramic or metal). The reader should be aware of these different terms.
An optical link can be classified as a length of fibre optic cable terminated at both ends with fibre optic termini. The optical link provides the transmission line between any two components via the optical termini which are typically housed within an interconnecting device (typically a connector) with tight tolerancing within the alignment mechanisms to ensure a low loss light transmission.
Part 001 will explain the need for high integrity terminations, provide an insight into component selection issues and suggests best practice when terminating fibres into termini for high integrity applications. A detailed review of the termination process can be found in section 4 of this part and is organised in line with the sequence of a typical termination procedure.
The vast number of cable constructions and connectors available make defining a single termination instruction that is applicable to all combinations very difficult. Therefore, this handbook concentrates on the common features of most termination practices and defining best practice for current to near future applications of fibre optics on aircraft. This has limited the studies within this part to currently available ‘avionic’ silica fibre cables and adhesive filled butt-coupled type connectors. Many of the principles described however would still be applicable for other termination techniques. Other types of termination are considered further in the repair part of this handbook.
It is noted that the adhesive based pot-and-polish process is applicable to the majority of single-way fibre optic interconnects connectors and termini for multi-way interconnects and connectors. They share this commonality.
1.2 Need to high integrity terminations
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Luft- und Raumfahrt - Faseroptische Systemtechnik - Handbuch - Teil 001: Anschlussverfahren und Werkzeuge
Teil 001 der EN 4533 untersucht die Anschlussaspekte von Lichtwellenleiterkabeln für Anwendungen in der Luft und Raumfahrt. Anschließen bezieht sich hierbei auf die Installation einer optischen Endstelle am Ende einer gepolsterten Faser oder eines Lichtwellenleiterkabels. Der Prozess umfasst mehrere Verfahren oder Praktiken, die nacheinander ausgeführt werden. Obgleich verschiedene Anschlüsse spezifische Anschluss¬verfahren aufweisen, teilen viele gemeinsame Elemente und diese werden in diesem Dokument besprochen. Ein Anschluss ist notwendig, um eine optische Verbindung zwischen zwei Netzwerk- oder Systemkompo¬nenten herzustellen oder Lichtwellenleiter zusammenzuführen.
Série aérospatiale - Systèmes des fibres optiques - Manuel d'utilisation - Partie 001 : Méthodes des terminaisons et des outils
La Partie 001 de l’EN 4533 examine la terminaison des câbles de fibres optiques utilisés dans les applications aérospatiales. La terminaison est l'action qui consiste à installer un contact optique à l'extrémité d'une fibre gainée ou d’un câble de fibre optique. Cette action comporte plusieurs modes opératoires ou méthodes séquentielles. Les contacts sont régis par des procédures de terminaison spécifiques ; cependant, nombre d'entre eux partagent des éléments communs qui sont exposés dans ce document. Une terminaison a pour obligation de former une liaison optique entre deux composants d'un réseau ou d'un système, ou d'accoupler des liaisons optiques.
Un contact de fibre optique comporte une ferrule de précision avec un trou central alésé à une tolérance rigoureuse pour recevoir la fibre optique (adéquatement collée en position et hautement polie). Un mécanisme d'alignement dans l’interconnexion (ou le connecteur) permet un alignement précis avec un autre contact (d'accouplement). De même que les ferrules monofibre, il est à noter l'existence de ferrules multifibres (par exemple : ferrules MT à transfert mécanique) qui sont également exposées dans cette partie du manuel d’installation.
La technologie à faisceau élargi est une autre technique d'accouplement de 2 fibres. Elle met en œuvre deux lentilles sphériques pour élargir, collimater et enfin, rétablir le centre optique du rayon lumineux en entrée et en sortie des fibres. Les contacts ne sont pas contraints ensemble, ce qui contribue à diminuer l'usure entre deux contacts tout en permettant d'augmenter les cycles de montage/démontage. Cette technologie est moins sensible aux défauts d'alignement et à la poussière. Les pertes optiques demeurent plus stables que les contacts à accouplement direct même si la perte nominale est plus élevée.
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Aeronavtika - Sistemi iz optičnih vlaken - Priročnik - 001. del: Metode določanja in orodja
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2020
Nadomešča:
SIST EN 4533-001:2009
Aeronavtika - Sistemi iz optičnih vlaken - Priročnik - 001. del: Metode določanja in
orodja
Aerospace series - Fibre optic systems - Handbook - Part 001: Termination methods and
tools
Luft- und Raumfahrt - Faseroptische Systemtechnik - Handbuch - Teil 001:
Verarbeitungsmethoden und Werkzeuge
Série aérospatiale - Systèmes des fibres optiques - Manuel d'utilisation - Partie 001 :
Méthodes des terminaisons et des outils
Ta slovenski standard je istoveten z: EN 4533-001:2020
ICS:
33.180.10 (Optična) vlakna in kabli Fibres and cables
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 4533-001
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2020
EUROPÄISCHE NORM
ICS 49.090 Supersedes EN 4533-001:2006
English Version
Aerospace series - Fibre optic systems - Handbook - Part
001: Termination methods and tools
Série aérospatiale - Systèmes des fibres optiques - Luft- und Raumfahrt - Faseroptische Systemtechnik -
Manuel d'utilisation - Partie 001 : Méthodes des Handbuch - Teil 001: Verarbeitungsmethoden und
terminaisons et des outils Werkzeuge
This European Standard was approved by CEN on 2 March 2018.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4533-001:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
Introduction . 6
a) The Handbook . 6
b) Background . 6
1 Scope . 7
1.1 General . 7
1.2 Need to high integrity terminations . 8
2 Normative references . 8
3 Component Selection . 8
3.1 Elements . 8
3.2 Fibre optic cables . 9
3.2.1 General . 9
3.2.2 Cable construction . 9
3.2.3 Fibre choice . 10
3.2.4 Cladding materials . 12
3.3 Primary buffer materials. 13
3.3.1 Function . 13
3.3.2 Acrylate . 13
3.3.3 Polyimide . 13
3.3.4 Silicone . 14
3.3.5 Strength Members . 14
3.4 Outer jacket . 14
3.5 Fibre optic interconnects (connectors) . 15
3.5.1 Introduction . 15
3.5.2 The Optical interface . 15
3.5.3 Single-way Interconnects/Connectors . 23
3.5.4 Multi-way Interconnects/Connectors . 23
3.5.5 Choice of tooling . 24
4 Health and safety aspects . 25
4.1 General . 25
4.2 Chemicals . 25
4.3 Sharps . 26
5 Termination process . 26
5.1 Objective . 26
5.2 Cable preparation . 26
5.2.1 General . 26
5.2.2 Cutting to length . 26
5.2.3 Removal of outer jacket . 28
5.2.4 Cable Handling tools (gripping the cable) . 33
5.2.5 Strength member trimming/ removal . 34
5.3 Removal of secondary coating(s) . 35
5.4 Removal of primary coatings . 36
5.4.1 General . 36
5.4.2 Mechanical techniques for primary coating removal . 36
5.4.3 Alternative techniques . 42
5.4.4 Troublesome coatings – Polyimide and Silicone . 43
5.4.5 Evidence of strength reduction when stripping primary buffer coatings . 45
5.4.6 To clean or not to clean . 46
5.5 Adhesives . 47
5.5.1 General . 47
5.5.2 Adhesive types . 47
5.5.3 The importance of glass transition temperature (T ) . 49
g
5.5.4 Epoxy cure schedule . 51
5.5.5 Usability. 53
5.5.6 Qualification . 57
5.6 Connector preparation . 57
5.6.1 Dry fitting . 57
5.7 Attachment of fibre to the terminus . 59
5.7.1 Application of adhesive . 59
5.7.2 Inserting Fibre ‘Best-Practice’ . 62
5.8 Adhesive cure . 66
5.8.1 General . 66
5.8.2 Orientation . 66
5.8.3 Curing equipment . 67
5.9 Excess Fibre removal . 71
5.9.1 General . 71
5.9.2 Post-cure rough cleaving . 71
5.9.3 Pre-cleave . 73
5.9.4 Safety . 73
5.9.5 Cleaving tools . 73
5.9.6 Sprung blade hand tools . 74
5.9.7 Cleaving fibres in Multi-fibre Ferrules .
...
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