EN 3475-705:2022
(Main)Aerospace series - Cables, electrical, aircraft use - Test methods - Part 705: Contrast measurement
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 705: Contrast measurement
This document specifies the process to be applied for measuring the contrast of wire and cable identification markings against the background of the unmarked wire insulation. It has been developed primarily to define a reproducible process of contrast value determination for use both to determine the intrinsic laser markability of wires at the time of manufacture or later, and to enable electrical wiring systems manufacturers to ensure that the whole process of wire marking is carried out to the required standard.
Luft- und Raumfahrt - Elektrische Leitungen für Luftfahrtverwendung - Prüfverfahren - Teil 705: Kontrastmessung
Dieses Dokument legt das zur Messung des Kontrasts von Leitungs- und Kabelkennzeichnungen vor dem Hintergrund der nichtgekennzeichneten Leitungsisolierung anzuwendende Verfahren fest. Es wurde vorrangig erstellt, um ein nachvollziehbares Verfahren zur Bestimmung des Kontrastwerts festzulegen, um sowohl die intrinsische Markierbarkeit mithilfe von Laser von Leitungen zum Zeitpunkt der Herstellung oder später zu bestimmen als es auch zu ermöglichen, dass Hersteller von elektrischen Leitungssystemen sicherstellen können, dass das gesamte Verfahren entsprechend der geforderten Norm durchgeführt wird.
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d'essais - Partie 705: Mesure de contraste
Le présent document spécifie le procédé à appliquer pour la mesure du contraste des marquages d'identification des fils et des câbles par rapport au fond de l’isolant des fils sans marquage. Il est essentiellement conçu pour définir un procédé reproductible de détermination de valeur de contraste à employer à la fois pour déterminer la marquabilité laser intrinsèque des fils pendant la fabrication ou ultérieurement, et permettre aux fabricants de systèmes de câblage électrique de garantir que l'ensemble du processus de marquage des fils est réalisé suivant la norme requise.
Aeronavtika - Električni kabli za uporabo v zračnih plovilih - Preskusne metode - 705. del: Meritev kontrasta
Ta dokument določa postopek, ki ga je treba uporabiti pri merjenju kontrasta identifikacijskih oznak na žicah in kablih glede na ozadje neoznačene izolacije žice. Oblikovan je bil predvsem za opredelitev ponovljivega postopka določanja vrednosti kontrasta, ki se uporablja tako za določanje intrinzične označljivosti žic z laserjem v času proizvodnje ali pozneje kot tudi za to, da lahko proizvajalci sistemov električnih napeljav zagotovijo, da je celoten postopek označevanja žic izveden v skladu z zahtevanim standardom.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2022
Nadomešča:
SIST EN 3475-705:2006
Aeronavtika - Električni kabli za uporabo v zračnih plovilih - Preskusne metode -
705. del: Meritev kontrasta
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 705: Contrast
measurement
Luft- und Raumfahrt - Elektrische Leitungen für Luftfahrtverwendung - Prüfverfahren -
Teil 705: Kontrastmessung
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d'essais -
Partie 705: Mesure de contraste
Ta slovenski standard je istoveten z: EN 3475-705:2022
ICS:
29.060.20 Kabli 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 3475-705
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2022
EUROPÄISCHE NORM
ICS 49.060 Supersedes EN 3475-705:2005
English Version
Aerospace series - Cables, electrical, aircraft use - Test
methods - Part 705: Contrast measurement
Série aérospatiale - Câbles électriques à usage Luft- und Raumfahrt - Elektrische Leitungen für
aéronautique - Méthodes d'essais - Partie 705: Mesure Luftfahrtverwendung - Prüfverfahren - Teil 705:
de contraste Kontrastmessung
This European Standard was approved by CEN on 8 November 2021.
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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3475-705:2022 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Preparation of samples . 6
5 Apparatus, measurement and process. 6
5.1 Apparatus . 6
5.1.1 Components of the measuring device . 6
5.1.2 Equipment colour . 6
5.1.3 Photometer . 7
5.1.4 Illumination and viewing system . 7
5.2 Measurement . 8
5.2.1 Equipment design and measurement methodology . 8
5.2.2 Measurement spot size . 8
5.2.3 Measurement area . 9
5.2.4 Calibration . 9
5.2.5 Measurement tolerance . 9
5.3 Process . 9
5.3.1 Precautionary measures . 9
5.3.2 Picture definition . 9
5.3.3 Sample area . 9
5.3.4 Number and location of measurements . 10
5.3.5 Determination of contrast values . 10
6 Requirements . 11
Bibliography . 12
European foreword
This document (EN 3475-705:2022) has been prepared by the Aerospace and Defence Industries
Association of Europe — Standardization (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-STAN, prior to its presentation to CEN.
This document shall be given the status of a national standard, either by publication of an identical text
or by endorsement, at the latest by August 2022, and conflicting national standards shall be withdrawn
at the latest by August 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
[This document supersedes EN 3475-705:2005.]
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this document: 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 the United
Kingdom.
Introduction
It is a requirement within the aerospace industry that all wires and cables within an aircraft electrical
system are identified with a circuit identification code at regular intervals down the length of the wire.
Various marking methods are used for marking these identification codes on to the surface of electrical
wires or cables including ink-based and laser-based processes. The legibility of the markings is
dependent upon the process used and the insulation medium. Minimum standards of contrast are
required to facilitate reading back of the identity codes.
NOTE It has been reported that there are instances where the contrast of marks on tape wrap wires is non-
uniform and can cause problems in the contrast measurement process which might lead to a non-conformance.
Care needs to be taken in such cases to establish a good average value of the contrast. This issue will be assessed
in the next revision of the document.
1 Scope
This document specifies the process to be applied for measuring the contrast of wire and cable
identification markings against the background of the unmarked wire insulation. It has been developed
primarily to define a reproducible process of contrast value determination for use both to determine
the intrinsic laser markability of wires at the time of manufacture or later, and to enable electrical
wiring systems manufacturers to ensure that the whole process of wire marking is carried out to the
required standard.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 3475-706, Aerospace series - Cables, electrical, aircraft use - Test methods - Part 706: Laser
markability
EN 4650, Aerospace series — Wire and cable marking process, UV Laser
CIE 15, Colorimetry
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at https://www.electropedia.org/
3.1
contrast
ratio of the difference in luminance between the marked and unmarked areas of the insulation divided
by the luminance of the unmarked insulation
3.2
luminance
quantitative measurement of the visible light reflected from a surface, in this case the wire or cable
insulation
3.3
laser
acronym for Light Amplification by the Stimulated Emission of Radiation
Note 1 to entry: Lasers are a source of intense monochromatic light in the ultraviolet, visible or infrared region
of the spectrum.
3.4
ultraviolet
UV
electromagnetic radiation in a wavelength range from approximately 200 nm to 400 nm
3.5
UV laser
laser that produces a beam of UV radiation
3.6
fluence
−2
energy density, measured in J/cm (Joules per square cm) of a single pulse of the laser
beam, which, for the purposes of this document, is taken at the surface of the wire insulation or cable
jacket
Note 1 to entry: See also EN 4650 for further details.
3.7
wavelength
λ
−9
measured in nanometres, nm. 1 nm = 10 m. λ = c/f where c is the velocity of light and f is the
frequency
4 Preparation of samples
The wire or cable samples shall be identified in accordance with the applicable manufacturing
instructions for the marking equipment. Where samples are to be UV laser-marked, this shall be done
using the fluence specified in EN 4650 or the relevant wire or aircraft manufacturer’s process
specification if different. When determining the laser markability of wires, this shall be in accordance
with EN 3475-706.
Take a sample of the wire for marking. Before marking the wire ensure that the wire surface is clean
and dry and free from dust and dirt, if necessary, wipe it clean using propan-2-ol (isopropyl alcohol).
The surfaces of the samples shall be clean and without damage.
The identification markings to be measured shall be even in colour and characters shall have well
defined edges.
Before starting measurements clean the surfaces with a soft, lint-free cloth, if required, to avoid
distortion of test results by a roughened surface or “deposits”.
5 Apparatus, measurement and process
5.1 Apparatus
5.1.1 Components of the measuring device
The measuring device shall comprise, at a minimum, a photometer, an illumination system and a
purpose designed sample holder suitable for wire and cable. The whole system shall be designed to
ensure that test results are not falsified by external influences. The photometer shall be designed to be
stable and free from vibrations and to exclude the influences of external light and reflections from
scattered light.
5.1.2 Equipment colour
The device for holding samples and any accessories and the equipment in the vicinity of the
measurement area shall be matt black in colour to absorb scattered light.
5.1.3 Photometer
The luminance shall be determined with a calibrated electrical photometer, which shall incorporate a
photopic filter to simulate the response of the human eye. The manufacturer’s instructions concerning
the photometer working range and operating instructions shall be observed. The measurement
sensitivity of the photometer shall be in conformity with CIE 15.
5.1.4 Illumination and viewing system
The illumination system shall consist of two light sources of equal
intensity (see Figure 1). The two sources may be two separate lamps or, preferably, two fibre lig
...
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