oSIST prEN 3475-705:2021

Aerospace series - Cables, electrical, aircraft use - 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 - Teil 705: Kontrastmessung

Série aérospatiale - Câbles électriques à usage aéronautique - 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 - 705. del: Meritev kontrasta

General Information

• Status: Not Published
• Public Enquiry End Date: 30-Sep-2021
• ICS: 29.060.20 - Cables
• ICS: 49.060 - Aerospace electric equipment and systems
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 16-Feb-2022
• Due Date: 23-Apr-2022
• Ref Project: EN 3475-705:2022 - Aerospace series - Cables, electrical, aircraft use - Test methods - Part 705: Contrast measurement

RELATIONS

• Revised: SIST EN 3475-705:2006 - Aerospace series - Cables, electrical, aircraft use - Test methods - Part 705: Contrast measurement
• Effective Date: 03-Apr-2019
• Replaces: SIST EN 3475-705:2006 - Aerospace series - Cables, electrical, aircraft use - Test methods - Part 705: Contrast measurement
• Effective Date: 16-Feb-2022

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 3475-705:2021
01-september-2021
Aeronavtika - Električni kabli za uporabo v zračnih plovilih - 705. del: Meritev
kontrasta

Aerospace series - Cables, electrical, aircraft use - Part 705: Contrast measurement

Luft- und Raumfahrt - Elektrische Leitungen für Luftfahrtverwendung - Teil 705:
Kontrastmessung

Série aérospatiale - Câbles électriques à usage aéronautique - Partie 705: Mesure de

contraste
Ta slovenski standard je istoveten z: prEN 3475-705
ICS:
29.060.20 Kabli Cables
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
oSIST prEN 3475-705:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 3475-705:2021
---------------------- Page: 2 ----------------------
oSIST prEN 3475-705:2021
DRAFT
EUROPEAN STANDARD
prEN 3475-705
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2021
ICS 49.060 Will supersede EN 3475-705:2005
English Version
Aerospace series - Cables, electrical, aircraft use - Part 705:
Contrast measurement

Série aérospatiale - Câbles électriques à usage Luft- und Raumfahrt - Elektrische Leitungen für

aéronautique - Partie 705: Mesure de contraste Luftfahrtverwendung - Teil 705: Kontrastmessung

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-

STAN.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3475-705:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 3475-705:2021
prEN 3475-705:2021 (E)
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

---------------------- Page: 4 ----------------------
oSIST prEN 3475-705:2021
prEN 3475-705:2021 (E)
European foreword

This document (prEN 3475-705:2021) 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 is currently submitted to the CEN Enquiry.
This document will supersede EN 3475-705:2005.
---------------------- Page: 5 ----------------------
oSIST prEN 3475-705:2021
prEN 3475-705:2021 (E)
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.
---------------------- Page: 6 ----------------------
oSIST prEN 3475-705:2021
prEN 3475-705:2021 (E)
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

electromagnetic radiation in a wavelength range from approximately 200 nm to 400 nm

---------------------- Page: 7 ----------------------
oSIST prEN 3475-705:2021
prEN 3475-705:2021 (E)
3.5
UV laser
laser that produces a beam of UV radiation
3.6
fluence

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

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 t
...