Bsi bs en 50411 3 6 2013

BS EN 50411-3-6:2013 BSI Standards Publication Fibre organisers and closures to be used in optical fibre communication systems — Product specifications Part 3-6: Multimode mechanical fibre splice for use in an outdoor protected environment (Cat U) BS EN 50411-3-6:2013 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 50411-3-6:2013 The UK participation in its preparation was entrusted to Technical Committee GEL/86/2, Fibre optic interconnecting devices and passive components A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2013 Published by BSI Standards Limited 2013 ISBN 978 580 74168 ICS 33.180.20 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2013 Amendments issued since publication Date Text affected BS EN 50411-3-6:2013 EN 50411-3-6 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM March 2013 ICS 33.180.20 English version Fibre organisers and closures to be used in optical fibre communication systems Product specifications Part 3-6: Multimode mechanical fibre splice for use in an outdoor protected environment (Cat U) Organiseurs et btiers de fibres destinés être utilisés dans les systèmes de communication par fibres optiques Spécifications de produits Partie 3-6: Epissure mécanique de fibres multimodales installée en environnement extérieur protégé (Cat U) LWL-Spleißkassetten und -Muffen für die Anwendung in LWL Kommunikationssystemen Produktnorm Teil 3-6: Mechanische Spleiße von Mehrmoden-Faser für geschützte Freiluftanwendungen (Kategorie U) This European Standard was approved by CENELEC on 2012-12-24 CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels © 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 50411-3-6:2013 E BS EN 50411-3-6:2013 EN 50411-3-6:2013 –2– Contents Foreword Scope 1.1 Product definition 1.2 Interoperability 1.3 Expected performance 1.4 Operating environment 1.5 Reliability 1.6 Quality assurance Normative references Description 3.1 General 3.2 Mechanical splice 3.3 Materials 3.4 Dimensions 3.5 Colour and marking Variants Dimensional requirements Tests 6.1 6.2 6.3 6.4 Test Introduction Test sample preparation Test and measurement methods Pass/fail criteria report Performance requirements 8.1 8.2 8.3 Annex A Dimensional and marking requirements Assembly yield requirement Optical performance requirements 10 (normative) Fibre type 16 Annex B (normative) Sample size and product sourcing requirements 17 Figures Figure – Outline and maximum dimensions Tables Table – Optical fibre mechanical splice, for category U – variants Table – Test details and requirements 10 Table A.1 – Fibre type characteristics 16 Table B.1 – Sample size per test 17 BS EN 50411-3-6:2013 –3– EN 50411-3-6:2013 Foreword This document (EN 50411-3-6:2013) has been prepared by CLC/TC 86BXA "Fibre optic interconnect, passive and connectorised components" The following dates are fixed: • • latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with this document have to be withdrawn (dop) 2013-12-24 (dow) 2015-12-24 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights BS EN 50411-3-6:2013 EN 50411-3-6:2013 –4– Fibre organisers and closures to be used in optical fibre communication systems – Product specifications Part 3-6: Multimode mechanical fibre splice for use in an outdoor protected environment (Cat U) Description Type: Fibre splice Style: Mechanical Operating wavelength: Fibre category Performance Application: EN 61753-1, Category U with extension of lower temperature to -40 °C 850 nm and 300 nm Attenuation grades ≤ 0,25 dB maximum (97 %) EN 60793-2-10 type A1a.1, A1a.2, A1a.3 and A1b Return loss grades ≥ 20 dB Related documents: EN 60793-2-10 Optical fibres – Part 2-10: Product specifications – Sectional specification for category A1 multimode fibres (IEC 60793-2-10) EN 60794-2-50 Optical fibre cables – Part 2-50: Indoor cables – Family specification for simplex and duplex cables for use in terminated cable assemblies (IEC 60794-2-50) EN 61300 series Fibre optic interconnecting devices and passive components – Basic test and measurement procedures (IEC 61300 series) Fibre optic interconnecting devices and passive components performance standard – Part 1: General and guidance for performance standards (IEC 61753-1) EN 61753-1 Outline and maximum dimensions: Variant Dimension W mm Dimension H mm Dimension L mm Type M1 3,8 6,4 38 Type M2 4,0 4,0 36 Type M3 3,2 3,2 45 Type M4 4,2 4,2 44 Type M5 4,0 4,0 40 Type M6 Ø 5,0 65 BS EN 50411-3-6:2013 –5– EN 50411-3-6:2013 Scope 1.1 Product definition This European Standard contains the initial, start of life dimensional, optical, mechanical and environmental performance requirements which a multimode mechanical splice will meet in order for it to be categorised as an EN standard product Since different variants and grades of performance are permitted, product marking and identification details are given in 3.5 Although in this document the product is qualified for EN 60793-2-10 type A1a.1, A1a.2, A1a.3 and A1b multimode fibres, it may also be suitable for other fibre types 1.2 Interoperability The installed mechanical splice fits into a fibre management system with optical fibre splice cassettes or splice trays This European Standard specifies the following two physical interface dimensions: • cross sectional profile with width, height or diameter (in millimetres); • length (in millimetres) 1.3 Expected performance In this document, the performance of a mechanical splice is given with identical fibres only Losses associated with fibre cladding diameter and mode field mismatch are not taken into account The measured attenuation is a function of the core concentricity, cladding non-circularity and alignment capability The optical return loss performance is a function of the index matching gel and the fibre end face preparation 1.4 Operating environment The tests selected combined with the severities and durations are representative of an outdoor enclosed environment defined as category U in EN 61753-1 To ensure that the product can be used in closures, boxes or street cabinet for categories A, G and S (as defined EN 61753-1) the specified lower temperature is extended to -40 °C and requirements for temporary flooding have been added 1.5 Reliability Whilst the anticipated service life expectancy of the product in this environment is 20 years, compliance with this specification does not guarantee the reliability of the product This should be predicted using a recognised reliability assessment programme 1.6 Quality assurance Compliance with this specification does not guarantee the manufacturing consistency of the product This should be maintained using a recognised quality assurance programme Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies EN 60793-2-10, Optical fibres — Part 2-10: Product specifications — Sectional specification for category A1 multimode fibres (IEC 60793-2-10) EN 61753-1, Fibre optic interconnecting devices and passive components performance standard — Part 1: General and guidance for performance standards (IEC 61753-1) EN 61300-2-1, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-1: Tests — Vibration (sinusoidal) (IEC 61300-2-1) BS EN 50411-3-6:2013 EN 50411-3-6:2013 –6– EN 61300-2-4, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-4: Tests — Fibre/cable retention (IEC 61300-2-4) EN 61300-2-5, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-5: Tests — Torsion/twist (IEC 61300-2-5) EN 61300-2-7, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-7: Tests — Bending moment (IEC 61300-2-7) EN 61300-2-9, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-9: Tests — Shock (IEC 61300-2-9) EN 61300-2-17, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-18: Tests — Cold (IEC 61300-2-17) EN 61300-2-18, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-18: Tests — Dry heat — High temperature endurance (IEC 61300-2-18) EN 61300-2-22, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-22: Tests — Change of temperature (IEC 61300-2-22) EN 61300-2-26, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-26: Tests — Salt mist (IEC 61300-2-26) EN 61300-2-27, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-27: Tests — Dust — Laminar flow (IEC 61300-2-27) EN 61300-2-33, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-33: Tests — Assembly and disassembly of closures (IEC 61300-2-33) EN 61300-2-45, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-45: Tests — Durability test by water immersion (IEC 61300-2-45) EN 61300-2-46, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 2-46: Tests — Damp heat cyclic (IEC 61300-2-46) EN 61300-3-3, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 3-3: Examinations and measurements — Active monitoring of changes in attenuation and return loss (IEC 61300-3-3) EN 61300-3-4, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 3-4: Examinations and measurements — Attenuation (IEC 61300-3-4) EN 61300-3-6, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 3-6: Examinations and measurements — Return loss (IEC 61300-3-6) EN 61300-3-28, Fibre optic interconnecting devices and passive components — Basic test and measurement procedures — Part 3-28: Examinations and measurements — Transient loss (IEC 61300-3-28) 3.1 Description General A multimode mechanical fibre splice is a passive optical interconnection component which provides optical and mechanical continuity between two optical fibres The products described in this specification are based on mechanical alignment of two cleaved fibres The fibres are protected against ingress of dust or water by a sealing material, generally an index matching gel, to both minimise reflections and to improve attenuation at the glass/gel/glass interface BS EN 50411-3-6:2013 –7– EN 50411-3-6:2013 Some splices may have a limited reinstallation capability In this case the re-installability shall be clearly stated and the re-installation test in 8.3 shall be conducted 3.2 Mechanical splice An optical fibre mechanical splice body contains the following pre-assembled elements: – an alignment device; – a sealing and index matching gel inside; – a fibre alignment activation device like a spring, wedge or plunger; – a fibre clamping or fixing able to withstand axial fibre loads Mechanical splices designed for use with cables shall contain strain relief fixing 3.3 Materials Materials which are not specified or which are not specifically described are left to the discretion of the manufacturer However, the following requirements shall be met – All materials that are likely to come in contact with personnel shall meet appropriate health and safety regulations – The sealing and index matching materials shall be compatible with the materials of the fibres and the mechanical splice parts – All components of the splice shall be resistant to solvents and degreasing agents that are typically used to clean and degrease fibres and cables – Metallic parts shall be resistant to the corrosive influences they may encounter during the lifetime of the product – Exterior polymer materials shall be resistant to mould growth 3.4 Dimensions Outline dimensions are specified All other dimensions are left to the discretion of the manufacturer 3.5 Colour and marking Marking of the product or packaging shall be in the following order of precedence: a) identification of manufacturer; b) manufacturing date code: year/week; c) manufacturer’s part number; d) variant identification number There is no preferred colour specified BS EN 50411-3-6:2013 EN 50411-3-6:2013 –8– Variants Table – Optical fibre mechanical splice, for category U – variants EN 50411–3–6 – XX1 – X2 – X3 Variant No XX1 M1 Mechanical splice Type M2 Mechanical splice Type M3 Mechanical splice Type M4 Mechanical splice Type M5 Mechanical splice Type M6 Mechanical cable splice Type Variant No X2 and X3 Mechanical splice type (common profile) Fibre types to be spliced P Primary coated 125/250 µm S Buffered 125/900 µm A Any single fibre types P or S R Reinforced cable Dimensional requirements Variant Description Dimension W ± 0,1 mm Dimension H ± 0,1 mm Dimension L ± mm mm mm mm Type M1 Mechanical Type M1 3,8 6,4 38 Type M2 Mechanical Type M2 4,0 4,0 36 Type M3 Mechanical Type M3 3,2 3,2 45 Type M4 Mechanical Type M4 4,2 4,2 44 Type M5 Mechanical Type M5 4,0 4,0 40 Type M6 Mechanical Type M6 Ø 5,0 Figure – Outline and maximum dimensions 65 BS EN 50411-3-6:2013 –9– EN 50411-3-6:2013 Tests 6.1 Introduction The mechanical and environmental performance of a fibre splice is vital to an optical cabling system The purpose of testing is to demonstrate that a mechanical splice remains functional under defined environmental conditions, without failures Optical performance testing is accomplished by subjecting the test specimen to a number of mechanical and environmental conditions and by measuring any optical performance deviations at prescribed intervals during and after completion of each test 6.2 Test sample preparation The test samples are prepared by making a mechanical splice on identical fibres Optical test samples shall be installed according to the manufacturers’ installation instructions The fibres for the optical test samples are multimode fibres as described in Annex A The length of the fibres shall be at least m on each side of the mechanical splice For each fibre construction (primary coated, buffered or reinforced cable) a number of test samples will be prepared as defined in Table B.1 6.3 Test and measurement methods All tests and measurement methods have been selected from EN 61300 series Unless otherwise stated in the individual test details, all attenuation measurements shall be performed at 850 nm ± 25 nm All specified optical losses are referenced to the initial attenuation at the start of the test A pass at 850 nm will also guarantee the performance at 300 nm No deviation from the specified test method is allowed Unless otherwise specified, tests should be carried out under standard atmospheric conditions according to EN 61300-1 6.4 Pass/fail criteria A product will have met the requirements of this European Standard provided no failures occur in any test In the event of a failure, the test shall be re run using a sample size double that of the original Test report Conformance to a performance standard shall be supported by a test report The test report shall clearly demonstrate that the tests described in Clause have been carried out in accordance with this standard and shall provide full details of the tests together with a pass/fail declaration In the case of a failure, an analysis of the cause of the failure shall be undertaken and any corrective actions taken shall be described If design changes are made, an assessment shall be carried out to determine whether full or partial requalification shall be done Performance requirements 8.1 Dimensional and marking requirements Dimensions and marking of the product shall be in accordance with the requirements of 3.5 and Clause 5, and shall be measured using the appropriate EN test method 8.2 Assembly yield requirement The success rate or yield of the assembly of mechanical splices depends on many variables (e.g installer skills, ambient conditions, condition of tools) Typically no direct feedback is given on the optical performance when a mechanical splice is made Therefore a small percentage of the installed splices might not meet the expected performance level BS EN 50411-3-6:2013 EN 50411-3-6:2013 – 10 – 8.3 Optical performance requirements Table – Test details and requirements No Test Attenuation Return loss Requirement Attenuation per splice: ≤ 0,25 dB Return loss per splice: ≥ 20 dB Details Method: EN 61300-3-4 Launch fibre length: ≥2m Source type: LED Launch conditions: As EN 61300-1 System stability: Better than ± 0,05 dB over the measuring period or at least h Detector linearity: ± 0,05 dB over the dynamic range to be measured Source central wavelengths: 850 nm ± 25 nm Method: EN 61300-3-6 method Launch fibre length: ≥2m Source type: LD Launch conditions: As EN 61300-1 System stability: Better than ± 0,05 dB over the measuring period or at least h Detector linearity: ± 0,05 dB over the dynamic range to be measured LD source central wavelengths: Splicing yield 100 splices will be made A minimum of 97 % shall meet the maximum attenuation requirement of test A minimum of 97 % shall meet the return loss requirement of test 850 nm ± 25 nm Method: EN 61300-3-4 insertion method EN 61300-3-6 method Launch fibre length: ≥ m Source type: LED for attenuation, LD for return loss Launch conditions: As EN 61300-1 System stability: Better than ± 0,05 dB over the measuring period or at least h Detector linearity: ± 0,05 dB over the dynamic range to be measured LD source central wavelengths: 850 nm ± 25 nm BS EN 50411-3-6:2013 – 11 – EN 50411-3-6:2013 Table – Test details and requirements (continued) No Test Vibration (sinusoidal) Shock Torsion Requirement Before and after the test the attenuation and return loss shall meet the requirements of tests and During the test the change in attenuation shall be ≤ ± 0,2 dB Before and after the test the attenuation and return loss shall meet the requirements of tests and Before and after the test the attenuation and return loss shall meet the requirements of tests and Details Method: EN 61300-2-1 Frequency range: 10 Hz - 55 Hz Constant vibration amplitude: 0,75 mm Number of sweeps (10-55-10 Hz): 15 Number of axis: The three main axes, perpendicular one to each other Duration per axis: 0,5 h Measurements required: Attenuation and return loss shall be measured before and after the test During the test the change in attenuation shall be measured by transient loss test method EN 61300-3-28 at 850 nm ± 25 nm Method: EN 61300-2-9 Acceleration force: 500 g Duration shock: ms half sine pulse Number of axes: main axes, perpendicular to each other Number of shocks: per axis (each in different direction) Measurements required: Before and after each axis Method: EN 61300-2-5 Magnitude of the load: 2,0 N ± 0,5 N for primary and buffered fibres 15 N ± N at N/s for aramid yarn reinforced cables Rate of load application: 0,1 N/s Load application point: 0,2 m from end of device Number of cycles: 10 cycles at ± 180° Measurements required: Attenuation and return loss shall be measured before and after the test BS EN 50411-3-6:2013 EN 50411-3-6:2013 – 12 – Table – Test details and requirements (continued) Test Fibre/cable retention Bending moment Assembly and disassembly of splices Requirement Before and after the test the attenuation and return loss shall meet the requirements of tests and Details Method: EN 61300-2-4 Load: 5,0 N ± 0,5 N for buffered fibres 2,0 N ± 0,5 N for primary coated fibres 70 N ± N for aramid yarn reinforced cables with diameter ≤ mm 100 N ± N for aramid yarn reinforced cables with diameter > mm Application point: 0,3 m from the end of device Load rate: 0,5 N/s for primary and buffered fibre N/s for aramid yarn reinforced cables Duration: 60 s Measurements required: Attenuation and return loss shall be measured before and after the test Before and after the test the attenuation and return loss shall meet the requirements of tests and Method EN 61300-2-7 Load: 2,0 N ± 0,1 N Duration: 10 s Measurements required: Attenuation and return loss shall be measured before and after the test Only for re-installable mechanical splices Before and after the test the attenuation and return loss shall meet the requirements of tests and Method: EN 61300-2-33 Conditioning between each installation: After each re-installation of the mechanical splice the splice shall be aged by temperature cycle (-40 °C to +70 °C) as specified in test 13 Number of re-installations: Measurements required: Attenuation and return loss shall be measured before, after each ageing cycle and after the test BS EN 50411-3-6:2013 – 13 – EN 50411-3-6:2013 Table – Test details and requirements (continued) No 10 11 Test Cold Dry heat Requirement During the test the maximum allowed change in attenuation is ≤ ± 0,2 dB During the test the return loss requirement of test shall be met Before and after the test the attenuation and return loss shall meet the requirements of tests and During the test the maximum allowed change in attenuation is ≤ ± 0,2 dB During the test the return loss requirement of test shall be met Before and after the test the attenuation and return loss shall meet the requirements of tests and Details Method: EN 61300-2-17 Pre-conditioning procedure: Standard atmospheric conditions for h Temperature: -40 °C ± °C Duration of the exposure: 96 h Operating wavelength: 850 nm ± 25 nm, Measurements required: Attenuation and return loss shall be measured before, and after the test During the test the change in attenuation and return loss shall be measured by test method EN 61300-3-3 Maximum sampling interval during the test: 1h Recovery procedure: Allow specimen to recover at room temperature for h Method: EN 61300-2-18 Pre-conditioning procedure: Standard atmospheric conditions for h Temperature: +70 °C ± °C Duration of the exposure: 96 h Operating wavelength: 850 nm ± 25 nm, Measurements required: Attenuation and return loss shall be measured before and after the test During the test the change in attenuation and return loss shall be measured by test method EN 61300-3-3 Maximum sampling interval during the test: 1h Recovery procedure: Allow specimen to return to room temperature for h BS EN 50411-3-6:2013 EN 50411-3-6:2013 – 14 – Table – Test details and requirements (continued) No 12 13 Test Damp heat, cyclic Change of temperature Requirement During the test the maximum allowed change in attenuation is ≤ ± 0,2 dB During the test the return loss requirement of test shall be met Before and after the test the attenuation and return loss shall meet the requirements of tests and During the test the maximum allowed change in attenuation is ≤ ± 0,2 dB During the test the return loss requirement of test shall be met Before and after the test the attenuation and return loss shall meet the requirements of tests and Details Method: EN 61300-2-46 Pre-conditioning procedure: Standard atmospheric conditions for h High temperature: +55 °C ± °C Low temperature: +25 °C ± °C Relative humidity: 93 % ± % Number of cycles: Duration of each cycle: 24 h Wavelength: 850 nm ± 25 nm, Measurements required: Attenuation and return loss shall be measured before and after the test During the test the change in attenuation and return loss shall be measured by test method EN 61300-3-3 Maximum sampling interval during the test: 15 Recovery procedure: Allow specimen to return to room temperature for h Method: EN 61300-2-22 (Test Nb) Pre-conditioning procedure: Standard atmospheric conditions for h High temperature: +70 °C ± °C Low temperature: -40 °C ± °C Number of cycles: 12 Rate of temperature change: °C/minute Duration at extreme temperatures: 1h Wavelength: 850 nm ± 25 nm Measurements required: Attenuation and return loss shall be measured before and after the test During the test the change in attenuation and return loss shall be measured by test method EN 61300-3-3 Maximum sampling interval during the test: 15 Recovery procedure: Allow specimen to return to room temperature for h BS EN 50411-3-6:2013 – 15 – EN 50411-3-6:2013 Table – Test details and requirements (continued) No 14 15 16 Test Dust – Laminar flow Salt mist Durability by water immersion Requirement Before and after the test the attenuation and return loss shall meet the requirements of tests and Before and after the test the attenuation and return loss shall meet the requirements of tests and No significant difference in visual aspect shall be noticed During the test the maximum allowed change in attenuation is ≤ ± 0,2 dB During the test the return loss requirement of test shall be met Before and after the test the attenuation and return loss shall meet the requirements of tests and Details Method: EN 61300-2-27 Preconditioning procedure: h at normal ambient conditions Temperature: +35 °C ± °C Relative humidity: 60 % ± % Dust type: Talc Dust particle diameter: < 150 µm Dust concentration: 25 g/m ± g/m Test duration: 10 Measurements required: Before and after the test, at standard atmospheric conditions Recovery procedure: Allow specimen to return to room temperature for h Method: EN 61300-2-26 Preconditioning procedure: h at normal ambient conditions Temperature: + 35 °C ± °C Salt solution (NaCl) concentration: 5%±1% pH: Between 6,5 and 7,2 Test duration: 96 h Measurements required: Before and after the test, at standard atmospheric conditions Recovery procedure: Allow specimen to return to room temperature for h Method: EN 61300-2-45 Preconditioning procedure: h at normal ambient conditions Temperature: + 45 °C ± °C Test duration: cycle of days Measurements required: Before and after the test, at standard atmospheric conditions Recovery procedure: Allow specimen to return to room temperature for h 3 BS EN 50411-3-6:2013 EN 50411-3-6:2013 – 16 – Annex A (normative) Fibre type Table A.1 – Fibre type characteristics Fibre type: EN 60793-2-10 Type A1a.1 or A1a.2 or A1a.3 Proof stress strain: ≥1% Core size: 50,0 µm ± 2,5 µm Core Non Circularity