SIST EN 3745-306:2025

Aerospace series - Fibres and cables, optical, aircraft use - Test methods - Part 306: Variation of attenuation during temperature cycling

This document specifies a method for checking the variation of attenuation of an optical cable during temperature cycling.

Luft- und Raumfahrt - Faseroptische Leitungen für Luftfahrzeuge - Prüfverfahren - Teil 306: Dämpfungsänderung bei Temperaturwechsel

Dieses Dokument legt ein Verfahren zur Prüfung der Dämpfungsänderung von Lichtwellenleiterkabeln bei Temperaturwechsel fest.

Série aérospatiale - Fibres et câbles optiques à usage aéronautique - Méthodes d'essais - Partie 306 : Variation de l'atténuation pendant le cyclage en température

Le présent document spécifie une méthode de vérification de la variation de l'atténuation d'un câble optique pendant le cyclage en température.

Aeronavtika - Optična vlakna in kabli za uporabo v zračnih plovilih - Preskusne metode - 306. del: Spreminjanje dušenja med cikličnimi temperaturnimi spremembami

Ta dokument določa metodo za preverjanje spreminjanja dušenja optičnega kabla med cikličnimi temperaturnimi spremembami.

General Information

• Status: Published
• Public Enquiry End Date: 19-Jul-2022
• Publication Date: 08-Apr-2025
• ICS: 33.180.10 - Fibres and cables
• ICS: 49.060 - Aerospace electric equipment and systems
• ICS: 49.090 - On-board equipment and instruments
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 08-Apr-2025
• Due Date: 13-Jun-2025
• Completion Date: 09-Apr-2025
• Ref Project: EN 3745-306:2025 - Aerospace series - Fibres and cables, optical, aircraft use - Test methods - Part 306: Variation of attenuation during temperature cycling

Relations

• Revised: oSIST prEN 3745-100:2025 - Aerospace series - Fibres and cables, optical, aircraft use - Test methods - Part 100: General
• Effective Date: 15-Oct-2025
• Revised: SIST EN 3745-306:2006 - Aerospace series - Fibres and cables, optical, aircraft use - Test methods - Part 306: Variation of attenuation during temperature cycling
• Effective Date: 18-Jan-2023

Overview

EN 3745-306:2025 - published by CEN as part of the Aerospace series - specifies a reproducible test method for checking variation of attenuation of optical fibres and cables during temperature cycling. It is intended for optical fibres and cables used in aircraft and defines specimen preparation, launch/detection conditions, continuous attenuation measurement and final acceptance checks to verify stability under thermal cycling.

Key topics and requirements

• Scope: Method for measuring how attenuation changes when an optical cable is subjected to temperature cycles (environmental qualification / durability test).
• Specimen preparation: Test samples must meet EN 3745-100 test conditions, be loosely coiled with a bend radius greater than the storage radius, terminated with suitable termini or pigtails, labelled for traceability and polished per IEC 61300-3-47 where required.
• Launch conditions: Light sources at 850 nm ± 30 nm and 1 300 nm ± 30 nm. A common-mode launch conditioner may be used; typical suitable launch condition noted is 85:85. Launch cables must match the fibre characteristics under test (e.g., 62.5 µm/125 µm graded-index, NA 0.275; 50 µm/125 µm; bend-insensitive 50/125).
• Measurement method: Continuous measurement of attenuation following EN 3745-301 (Method C) while performing the specified number of temperature cycles per EN 3745-402.
• Acceptance and inspection: The maximum allowable increase in attenuation is defined in the applicable product standard; after testing, specimens are examined for damage in accordance with EN 3745-201.
• Traceability & conformity: Test setup and results should be traceable to product-standard requirements; this edition supersedes EN 3745-306:2005 and aligns with ASD-STAN/CEN rules.

Practical applications and users

• Aerospace OEMs and system integrators validating optical cable performance for airborne systems.
• Cable and connector manufacturers performing qualification and production verification.
• Independent environmental and fiber-optic test laboratories running standardized temperature cycling attenuation tests.
• Procurement, quality and certification engineers who require proof of stable optical performance across service temperature ranges.
• Use cases include qualification of flight-critical data links, in-cabin and avionic fibre runs, and supplier acceptance testing.

Related standards

• EN 3745-100 (General requirements for aerospace optical fibre tests)
• EN 3745-301 (Attenuation measurement - Method C)
• EN 3745-402 (Temperature cycling procedure)
• EN 3745-201 (Visual examination)
• EN 2591-100 (Launch condition guidance)
• IEC 61300-3-47 (End-face geometry / interferometry)

Keywords: EN 3745-306:2025, aerospace optical cable testing, variation of attenuation, temperature cycling, optical fibres aircraft use, CEN test methods, launch conditions, attenuation measurement.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2025
Aeronavtika - Optična vlakna in kabli za uporabo v zračnih plovilih - Preskusne
metode - 306. del: Spreminjanje dušenja med cikličnimi temperaturnimi
spremembami
Aerospace series - Fibres and cables, optical, aircraft use - Test methods - Part 306:
Variation of attenuation during temperature cycling
Luft- und Raumfahrt - Faseroptische Leitungen für Luftfahrzeuge - Prüfverfahren - Teil
306: Dämpfungsänderung bei Temperaturwechsel
Série aérospatiale - Fibres et câbles optiques à usage aéronautique - Méthodes d'essais
- Partie 306 : Variation de l'atténuation pendant le cyclage en température
Ta slovenski standard je istoveten z: EN 3745-306:2025
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 3745-306
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 49.090 Supersedes EN 3745-306:2005
English Version
Aerospace series - Fibres and cables, optical, aircraft use -
Test methods - Part 306: Variation of attenuation during
temperature cycling
Série aérospatiale - Fibres et câbles optiques à usage Luft- und Raumfahrt - Faseroptische Leitungen für
aéronautique - Méthodes d'essais - Partie 306 : Luftfahrzeuge - Prüfverfahren - Teil 306:
Variation de l'affaiblissement pendant le cyclage en Dämpfungsänderung bei Temperaturwechsel
température
This European Standard was approved by CEN on 2 September 2024.

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, Türkiye 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3745-306:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Preparation of specimens . 4
4.1 Specimens . 4
4.2 Test conditions . 5
5 Launch conditions. 5
6 Method . 5
6.1 Procedure . 5
6.2 Final measurements and requirements . 5
Bibliography . 6

European foreword
This document (EN 3745-306:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-
...