1、BRITISH STANDARD AEROSPACE SERIES BS EN 3475-706:2005 Cables, electrical, aircraft use Test methods Part 706: Laser markability The European Standard EN 3475-706:2005 has the status of a British Standard ICS 49.060 Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontrolled Copy, (c) BSI
2、BS EN 3475-706:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 10 February 2006 BSI 10 February 2006 ISBN 0 580 47797 5 National foreword This British Standard is the official English language version of EN 3475-706:2005. The UK particip
3、ation in its preparation was entrusted by Technical Committee ACE/6, Aerospace avionic electrical and fibre optic technology, to Subcommittee ACE/6/-/2, Aerospace Cables, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committe
4、e any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-reference
5、s The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Sta
6、ndards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front co
7、ver, an inside front cover, the EN title page, pages 2 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontr
8、olled Copy, (c) BSIEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN3475706 October2005 ICS49.060 EnglishVersion AerospaceseriesCables,electrical,aircraftuseTest methodsPart706:Lasermarkability SriearospatialeCbleslectriquesusage aronautiqueMthodesdessaisPartie706: MarquabilitlaserUV LuftundRaumfahr
9、tElektrischeLeitungenfr LuftfahrtverwendungPrfverfahrenTeil706:UVLaser Markierung ThisEuropeanStandardwasapprovedbyCENon12September2005. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalte
10、ration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmember
11、intoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway
12、,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2005CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnatio
13、nalMembers. Ref.No.EN3475706:2005:E Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontrolled Copy, (c) BSIEN 3475-706:2005 2 Contents Page Foreword 3 Introduction4 1 Scope .4 2 Normative references .4 3 Terms and definitions.4 4 Requirements 6 Licensed Copy: Wang Bin, na, Mon May 08 0
14、3:45:17 BST 2006, Uncontrolled Copy, (c) BSIEN 3475-706:2005 3 Foreword This European Standard (EN 3475-706:2005) has been prepared by the European Association of Aerospace Manufacturers - Standardization (AECMA-STAN). After enquiries and votes carried out in accordance with the rules of this Associ
15、ation, this Standard has received the approval of the National Associations and the Official Services of the member countries of AECMA, prior to its presentation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsem
16、ent, at the latest by April 2006, and conflicting national standards shall be withdrawn at the latest by April 2006. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying
17、any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Icel
18、and, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontrolled Copy, (c) BSI4 Introduction UV laser wire marking is the ae
19、rospace industry standard method for marking identification codes on to the surface of electrical wires or cables. UV laser wire marking was developed in 1987 to provide a safe, permanent means of marking thin wall insulations in particular, as an alternative to hot stamp wire marking, which is cons
20、idered to be an aggressive process. 1 Scope This standard specifies the test method to establish the ultra violet (UV) laser marking performance of aerospace wire and cable for use in conjunction with UV laser wire marking systems in accordance with TR 4543 “UV laser wire marking systems for aircraf
21、t wire and cable identification” and EN 3475-100 “Aerospace series Cables, electrical, aircraft use Test methods Part 100: General”. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies.
22、 For undated references, the latest edition of the referenced document (including any amendments) applies. EN 3838, Aerospace series Requirements and tests on user-applied markings on aircraft electrical cables. 1)EN 3475-100, Aerospace series Cables, electrical, aircraft use Test methods Part 100:
23、General. EN 3475-705, Aerospace series Cables, electrical, aircraft use Test methods Part 705: Contrast measurement. TR 4543, UV laser wire marking systems for aircraft wire and cable identification. 2)3 Terms and definitions For the purposes of this document, the following terms and definitions app
24、ly. 3.1 laser 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 laser beam is generat
25、ed by energising the active medium using an external power source, which is most commonly electrical or optical. 3.2 ultraviolet (abbreviation UV) electromagnetic radiation in a wavelength range from approximately 200 nm to 400 nm 1) Published as AECMA Prestandard at the date of publication of this
26、standard. 2) In preparation at the date of publication of this standard. EN 3475-706:2005 Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontrolled Copy, (c) BSI5 3.3 UV laser a laser that produces a beam of UV radiation 3.4 fluence the energy density, measured in J cm 2(Joules per squ
27、are cm) of a single pulse of the laser beam, which, for the purposes of this document, is at the surface of the wire insulation or cable jacket 3.5 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 a
28、s FWHM full width half maximum. Pulse lengths are measured in nanoseconds, ns. 1 ns = 10 9s. 3.6 wavelength () wavelength is measured in nanometres, nm. 1 nm = 10 9m. = c/f where c is the velocity of light and f is the frequency 3.7 damage for the purpose of this document, damage is defined as an un
29、acceptable reduction in the mechanical or electrical properties of a wires insulation, i.e. specifically a measurable reduction in the performance of the wire which is outside of its defined and acceptable specification Wire surface defects that are visible only through 10 magnification or greater,
30、such as bubbles or flakes, should not be considered as damage unless they would affect marking performance (contrast, legibility, or other behaviour according to EN 3838) or other properties of the wire insulation. 3.8 Nd (neodymium) neodymium is an elemental metal that forms the active laser materi
31、al in the most common type of solid state laser. The neodymium is held in an optically transparent solid “host” material, and is energised 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 influen
32、ce the laser wavelength. Typical host materials are specialised crystal materials, such as Yttrium Aluminium Garnet (YAG) and Yttrium Lithium Fluoride (YLF). These lasers are commonly referred to as Nd:YAG or Nd:YLF respectively. The primary wavelength of Nd solid state lasers is in the infrared (IR
33、) at a wavelength of approximately 1 064 nm. The IR output of such lasers can be conveniently reduced to lower wavelengths suitable for wire marking by use of harmonic generation (see 3.10). 3.9 excimer a gas laser deriving its name from the term “excited dimer”. The laser is energised by means of a
34、 gas discharge. Excimer lasers are available operating at a number of discrete wavelengths throughout the UV, the most common of which are 193 nm, 248 nm, 308 nm and 351 nm. The wavelength is dependant only on the gas mix used; 308 nm is commonly used for UV laser wire marking. 3.10 harmonic generat
35、ion the use of non-linear optical processes to change the wavelength of a laser by frequency conversion. This enables the output of an infrared laser to be converted to shorter wavelengths. In the case of Nd lasers this results in a frequency doubled output at 532 nm in the green and a frequency tri
36、pled output at 355 nm in the UV, which is used for wire marking. EN 3475-706:2005 Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontrolled Copy, (c) BSI6 4 Requirements 4.1 General 4.1.1 Preparation of wire samples Take a sample of the wire for marking. Before marking the wire ensure
37、that the wire surface is clean and dry and free from dust and dirt. For initial production it should only be necessary to clean the wire with a dry cloth. However, in some situations, for instance if the wire is contaminated with oil or is very dirty, it may be necessary to wipe it clean using Propa
38、n-2-ol (Isopropyl alcohol). 4.1.2 Laser marking system A suitable laser must be used to mark the wire samples. Based on commonly used laser sources employed in UV laser wire marking systems within the aerospace industry, it is recommended that either one of the ultra violet (UV) laser types listed i
39、n the following Table 1 is used for marking the wire samples. These are pulsed lasers that provide the very short pulse lengths and intense, high power pulses of UV light required for creating marks on aerospace wire insulation. The laser pulse length shall be within the range of 1 ns to 30 ns. Tabl
40、e 1 Laser type Wavelength nm Pulse length ans Frequency tripled Q-switched Neodymium YAG, (Nd:YAG), solid state laser 355 4 to 20 Xenon chloride (XeCl) excimer gas laser 308 10 to 30 aThe pulse length ranges quoted are typical of commercially available lasers. IMPORTANT Other laser types may only be
41、 employed provided they comply with the requirements of TR 4543. To measure the marking performance of the wire it is necessary to measure the contrast of the mark made by the UV laser beam. The mark should be made using a laser and optical beam delivery system that incorporates a mask with a suitab
42、le cut out, e.g. in the shape of a square or rectangle, so that a clearly defined mark can be made on the wire surface for measurement. See Figure 1. To enable the mark contrast to be accurately measured, a well-formed mark with minimum dimensions of (1 1) mm is required, subject to the wire gauge b
43、eing large enough to accommodate this. See Figure 2. It is important that the intensity of that part of the laser beam used for marking the samples and subsequent contrast measurement should be uniform to within 10 % when projected on to a flat surface at the focal point of the beam delivery system.
44、 This is to ensure that fluctuations in the mark contrast due to changes in the laser intensity within the marking field are kept to a minimum. To ensure that this is the case suitable, purpose designed test equipment must be used for the laser marking, or alternatively, appropriate diagnostic equip
45、ment must be used to confirm that the laser beam intensity is within the required limits. Figure 3 shows an acceptable laser beam profile. IMPORTANT The contrast achieved may vary for certain combinations of wire types and lasers, in particular wires with ethylenetetrafluoroethylene extruded insulat
46、ions, whether cross linked or non-cross linked, are likely to exhibit a higher contrast with 355 nm Nd:YAG lasers than with 308 nm excimer lasers. It is therefore important to record the type of laser used in the tests. In general, wires with insulations made from polytetrafluoroethylene are unlikel
47、y to exhibit this tendency. EN 3475-706:2005 Licensed Copy: Wang Bin, na, Mon May 08 03:45:17 BST 2006, Uncontrolled Copy, (c) BSI7 4.1.3 Laser marking fluence Marking should be carried out as follows: A marking fluence of (0,9 0,1) J cm 2should be used unless the wire type under test is specified f
48、or marking at a different fluence. This fluence level has been determined to be satisfactory for achieving the maximum contrast, or satisfactory contrast levels, on all common aerospace wire and cable types and is representative of the majority of equipment in use, albeit that some equipment does function with higher fluence levels. It should be noted that the fluence is specified here for the purposes of defining the requirements for determining the laser markability of the wire only. The system used
