1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2015 SAE InternationalAll rights reserved. No part of this publi
3、cation may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AIR5558AEROSPACEINFORMATION REPORTAIR5558Issued 2009-05Reaffirmed 2015-12Ultraviolet (UV) Las
5、er Marking Performance of Aerospace Wire ConstructionsRATIONALEAIR5558 has been reaffirmed to comply with the SAE five-year review policy.TABLE OF CONTENTS 1. SCOPE . 22. REFERENCES. 23. DEFINITIONS 24. BACKGROUND . 35. OBJECTIVE . 46. WIRE MARKING PROCESS . 47. WIRE MARKING CONTRAST- TEST METHOD .
6、48. TEST RESULTS 59. CONCLUSION . 910. NOTES . 91. SCOPE The purpose of this report is to provide information on the results of ultra violet (UV) laser marking and mark contrast measurement of a wide range of aerospace wire and cable constructions, the specifications for most of which do not state s
7、pecific requirements for laser markability. The contents of this document are for information and guidance only. It is not intended that it be used as the basis for marking process specifications or standards, which are covered by AS5649 Wire and Cable Marking Process, UV Laser. 2. REFERENCES The fo
8、llowing publications for a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of the other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document
9、 and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0
10、001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AIR5468 Ultraviolet (UV) Lasers For Aerospace Wire Marking AS5649 Wire and Cable Marking Process, UV Laser AS4373 Test Methods for Insulated Electric Wire ARP5607 Legibility of Print on Aerospace Wires and Cab
11、les AS50881 Wiring Aerospace Vehicle 3. DEFINITIONS For the purpose of this document the following terms and definitions apply.CABLE: Electrical cable, unless noted as a fiber optic cable. Two or more insulated conductors, solid or stranded, contained in a common covering, or two or more insulated c
12、onductors twisted or molded together without common covering, or one insulated conductor with a metallic covering shield or outer conductor. CONTRAST: A measurement relating to the difference in luminance of the mark and its associated background according to a precise formula. EXCIMER: A gas laser
13、deriving its name from the term “excited dimer”. The laser is energized by means of an electrical discharge in a specialized mixture of rare gases and halogens. Excimer lasers are available operating at a number of discrete wavelengths throughout the UV, the most common of which are 193, 248, 308 an
14、d 351 nm. The wavelength is dependant only on the gas mix used; 308 nm is commonly used for UV laser wire marking. FLUENCE: The energy density, measured in J cm-2 (Joules per square cm) of a single pulse of the laser beam, which for the purposes of this standard is at the surface of the wire insulat
15、ion or cable jacket. INFRARED: (Abbreviation IR) Electromagnetic radiation in the wavelength range from approximately 700 nm to in excess of 10 000 nm. INSULATION: For the purposes of this standard the outer polymer covering of an electrical wire or multi-conductor cable or fiber optic cable. SAE IN
16、TERNATIONAL AIR5558 2 OF 9LASER: Laser is an acronym for Light Amplification by the Stimulated Emission of Radiation. Lasers are a source of intense monochromatic light in the ultraviolet, visible or infrared region of the spectrum. The “active” or lasing medium may be a solid, liquid or gas; the la
17、ser beam is generated by energizing the active medium using an external power source, which is most commonly electrical or optical. LEGACY WIRE TYPES: Wire types defined by a specification that has no laser marking requirements. LEGIBILITY: Properties of a mark that enable it to be easily and correc
18、tly read. LUMINANCE: The quantitative measurement of the visible light reflected from a surface, in this case the wire or cable insulation.MARK: A meaningful alphanumeric or machine readable mark applied to the surface of a wire or cable jacket. MARKABILITY: The ability of a wire construction to be
19、marked to provide legible identification marks of a specified contrast when marked in accordance with this standard. NEODYMIUM: (Abbreviation Nd) Neodymium is an elemental metal that forms the active laser material in the most common type of solid state laser. The neodymium is held in an optically t
20、ransparent solid “host” material, and is energized by optical input, either from a flash lamp or from the optical output from a diode laser. The host material does not play a direct role, but can slightly influence the laser wavelength. Typical host materials are specialized crystal materials such a
21、s Yttrium Aluminum Garnet (YAG), Yttrium Lithium Fluoride (YLF) and Yttrium Vanadate (YVO4). These lasers are commonly referred to as Nd:YAG, Nd:YLF and Nd:YVO4 respectively. The primary wavelength of Nd solid state lasers is in the infrared (IR) at a wavelength of approximately 1064 nm. The IR outp
22、ut of such lasers can be conveniently reduced to lower wavelengths suitable for wire marking by use of harmonic generation. PULSE LENGTH: The time interval between the laser energy crossing half the maximum energy on the rising and the falling edges of the pulse; referred to as FWHM full width half
23、maximum. Pulse lengths are normally measured in nanoseconds.ULTRAVIOLET: (Abbreviation UV) Electromagnetic radiation in the wavelength range from approximately 200 nm to 400 nm.UV LASER: A laser that produces a beam of radiation in the UV range. WAVELENGTH: () Wavelength is the distance between repe
24、ating units of a wave pattern, e.g. the distance between the crest of one wave and the crest of an adjacent wave. Laser wavelength is typically measured in nanometres. = c/f where c is the velocity of light and f is the frequency.WIRE: A single metallic conductor of solid, stranded or tinsel constru
25、ction, designed to carry current in an electric circuit, but not having a metallic covering, sheath or shield. For the purpose of this standard “wire” refers to insulated electric wire.4. BACKGROUND A wide variety of wire constructions have been used over the years on numerous military and civil air
26、craft. In many instances it has not been considered practicable to update wire constructions to newer types on later production models due to implementation costs and potential changes that might be required in maintenance documentation and procedures. Modification programs in which new systems are
27、added often utilize the same wire and cable types that were originally employed on the aircraft at the time of manufacture. The result has been a large scale continued use of wire and cable types that originated quite some time ago. Due to their age, the specifications for these wire and cable types
28、 predate the introduction of newer processes such as UV laser wire marking and hence do not include a requirement for markability. Such wire and cable is referred to as “legacy wire” within this document. SAE INTERNATIONAL AIR5558 3 OF 9Over time there have been significant improvements in process t
29、echnology, including the introduction of UV laser wire marking of the type described in SAE AIR5468 and covered by SAE AS5649. Despite the fact that many legacy wire constructions are suitable for UV laser marking the specifications for these constructions have not been changed to add such requireme
30、nts. Also, while specifications for some modern wire constructions have been documented to include requirements for laser markability, others have not. However, the employment of titanium dioxide as a common coloring agent in most currently used white and light colored insulation materials usually p
31、ermits the use of non-invasive UV laser wire marking to provide acceptable legibility and durability. 5. OBJECTIVE When considering the possible employment of UV laser marking on various wire or cable types, organizations undertaking wire marking activities have a need to understand the levels of co
32、ntrast and legibility that may be expected, the equipment needed and the fluence, pulse duration and wavelength settings required to achieve these results. The process requirements utilized for the tests are described in detail in SAE AS5649, Wire and Cable Marking Process, UV Laser. Aerospace vehic
33、le manufacturers will also need assurance that the properties of individual wire and cable constructions are not adversely affected by this process.The intent of the UV laser marking test program described in this document is to provide information about results that have been achieved when marking
34、many of the commonly used wire types that are used in new equipment, maintenance and modification programs. Information is also included for comparison with those few wire specifications that define a specific requirement for UV laser mark contrast. 6. WIRE MARKING PROCESS In all cases wires and cab
35、les were laser marked in accordance with the required process parameters specified in AS5649 in order to establish their laser marking performance; details of process parameters are provided in Table 1. 7. WIRE MARKING CONTRAST- TEST METHOD Laser marking tests of represenative samples of the wires a
36、nd cables noted in Table 1 have been conducted in accordance with the requirements stated in AS4373 Method 1001, which provides an assessment of the specific level of contrast between the identification marks and the background wire insulation. This method is limited to white and to other light colo
37、red insulation materials.This method has been developed primarily to define a reproducible process of contrast value assessment for determining the legibility of identification marks. Its use is intended to provide an objective means of determination of the contrast value of wire types tested as a m
38、easure of their intrinsic laser markability.SAE INTERNATIONAL AIR5558 4 OF 98. TESTRESULTSTABLE 1 TYPICAL CONTRAST RANGEFOR LASER MARKING OFAEROSPACEWIRE AND CABLE TESTSPECIMEN somewires are manufacturedwitha pigmented outer layer which makesit laser markable.Some wires have atransparent non-markabl
39、e outerlayer. Althoughthe inner layer may markinsuchcases, usersshould establish themake up of thewiretheyare using andwhether itissuitablefor laser marking.“ Samplesquoted witha superscript after the value have not beentested but fall within a group of samples withthe same insulation type of which
40、at least one constituent of that grouphas been testedtoproduce aresult. Notes: 1. The followinggeneralguideline for mark contrast canbeusedinevaluatingwireconstructions for Laser Markability andresultant legibility: 80%- excellent 50-60%- moderate 70-80% - verygood40-50%- marginal 60-70% - good 40%-
41、 poor -likelytobeillegible When determininglegibility in accordancewiththe recommendations statedinARP5607, the legibilityofwiremarkings documentedinthis reportare consideredtobeinanacceptablerange in normal light conditions where theindicated contrast is 50% or greater. For military applications un
42、der lowlight level conditions, an indicated contrast minimum of 55% is consideredtobeacceptableasrequired by thelegibility requirements of AS50881. 2. In allinstances, no detrimentaleffectswereobservable onthe insulation characteristics of thesubject test specimens under 10Xmagnification. Wirespecim
43、ens invariably wouldbecapableofmeeting theinsulationresistanceand dielectricwithstandrequirementsstated in their original specification. 3. XLETFE, ETFE and PVDFwireinsulations marked with 308 nmexcimer laserswill typicallyshow a reducedcontrast,some 5 -10% lower than that obtained with355 nm freque
44、ncytripled Nd:YAGlasers usedand reportedabove in Table 1. 4. The results quotedinthe abovetablehavebeenprovided froma reportand internal study undertakenbySpectrumTechnologies PLC, Bridgend, UnitedKingdom, inwhich markingand contrast measurement werecarried out in house using thecompanysown equipmen
45、t.SAE INTERNATIONAL AIR5558 8 OF 99. CONCLUSION The intent of this information report is to provide a guide to the intrinsic laser markability of the many and varied legacy and other wire types commonly used in air vehicle equipment, manufacturing, maintenance activities and modification programs. D
46、ue to allowable differences in insulation material combined with variations between manufacturers and between manufacturing batches it is not possible to assure that the levels of contrast stated in this AIR will be obtained in all cases when marking the referenced wires except for qualified non-leg
47、acy wire types. This report does, however provide a fair indication of the general markability of wire types having specifications that do not express specific requirements for UV laser marking performance. 10. NOTES 10.1 A change bar (|) located in the left margin is for the convenience of the user
48、 in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY SAE SUBCOMMITTEE AE-8A, SYSTEMS INSTALATION, OF COMMITTEE AE-8, AEROSPACE ELECTRICAL/ELECTRONIC DISTRIBUTION SYSTEMS SAE INTERNATIONAL AIR5558 9 OF 9
