oSIST prEN 13523-3:2023

Coil coated metals - Test methods - Part 3: Colour difference and metamerism - Instrumental comparison

This document specifies procedures for determining the instrumental colour difference (CIELAB) of an organic coating on a metallic substrate compared to another one used as a reference (usually called reference) and the metamerism depending on the illuminant.
When two colour specimens have identical spectral reflectance curves, they are matching under any illuminant irrespective of its spectral characteristics. This is termed a “spectral match”. It is also possible for two colour specimens having different spectral reflectance curves to match visually under a given light source but not to match under another light source with different spectral characteristics; such matches are termed “metameric”.
One quantitative description of metamerism is the so-called “metamerism index”.
Information on the metamerism index is of limited value where ΔE (instrumental colour difference for a given illuminant) is > 0,5. The metamerism index is not suited for determining the absolute colour difference or colour consistency of a given specimen at change of illuminant.
The colour difference under the reference illuminant is to be measured in colour coordinates L*, a* and b*.
Excluded from this method are organic coatings producing fluorescence and/or which are multicoloured, pearlescent or metallic.
Establishing a reference as well as the magnitude of an acceptable colour difference are not covered by this method.
Two methods are given in this document:
a)   instrumental colour difference measurement using a tristimulus colourimeter;
b)   instrumental colour difference measurement using a spectrophotometer or equivalent.
It is advised that care is taken when measuring e.g.
—   textured surfaces;
—   fluorescent coatings;
—   metameric coatings;
—   multi-coloured, pearlescent, metallic or special colour effect coatings.

Bandbeschichtete Metalle - Prüfverfahren - Teil 3: Farbabstand und Metamerie - Farbmetrischer Vergleich

Dieses Dokument legt Verfahren zur farbmetrischen Bestimmung des Farbabstandes (CIELAB ΔE_Lab^* oder 〖ΔE〗_00) einer organischen Beschichtung auf einem metallischen Substrat im Vergleich mit einer anderen, die als Referenz verwendet wird (üblicherweise Referenz genannt), und die Metamerie in Abhängigkeit von der Lichtart fest.
Wenn zwei Farbproben identische spektrale Reflexionskurven aufweisen, ist ihre Farbe bei jeder Lichtart unabhängig von deren spektralen Eigenschaften gleich. Dies wird „unbedingt gleich“ genannt. Es ist auch möglich, dass zwei Farbproben, die unterschiedliche spektrale Reflexionskurven aufweisen, unter einer bestimmten Lichtquelle gleich aussehen, jedoch nicht unter einer anderen Lichtquelle mit anderen spektralen Eigenschaften. Dies wird „metamer“ genannt.
Eine quantitative Beschreibung der Metamerie ist der „Metamerie-Index“.
Die Angabe des Metamerie-Index ist von begrenztem Wert, wenn ΔE (der gemessene Farbabstand für eine bestimmte Lichtart) > 0,5 ist. Der Metamerie-Index ist nicht zum Bestimmen des absoluten Farbabstands oder der Farbkonstanz einer bestimmten Probe bei Lichtartwechsel geeignet.
Der Farbabstand unter der Bezugslichtart ist durch die Farbmaßzahlen L*, a* und b* zu messen.
Von diesem Verfahren ausgeschlossen sind fluoreszierende Beschichtungen, mehrfarbige Proben, Proben mit Metallic-Beschichtungen und Proben, die Perlglanzeffekte aufweisen.
Die Festlegung einer Referenz sowie der Größenordnung eines annehmbaren Farbabstandes sind nicht Gegenstand dieses Verfahrens.
Zwei Verfahren sind in diesem Dokument angegeben:
   farbmetrische Messung des Farbabstandes mit einem Dreibereichs-Farbmessgerät;
   farbmetrische Messung des Farbabstandes mit einem Spektralphotometer oder einem gleichwertigen Gerät.
Es wird empfohlen, dass bei z. B. folgenden Messungen besonders sorgfältig gearbeitet wird:
   strukturierte Oberflächen;
   fluoreszierende Beschichtungen;
   Beschichtungen mit Metamerie;
   mehrfarbige Beschichtungen, Beschichtungen mit Perlglanzeffekt, Metallic-Beschichtungen oder Beschichtungen mit besonderem Farbeffekt.

Tôles prélaquées - Méthodes d'essai - Partie 3 : Différence de couleur et métamérisme - Comparaison au moyen d'instruments

Le présent document spécifie les modes opératoires permettant de déterminer, au moyen d’instruments, la différence de couleur (CIELAB   ou  ) d’un revêtement organique sur un subjectile métallique par rapport à un autre revêtement utilisé comme référence (généralement appelé « référence »), ainsi que le métamérisme dépendant de l’illuminant.
Lorsque deux éprouvettes de couleur ont des courbes de réflexion spectrale identiques, les couleurs correspondent quels que soient l’illuminant et ses caractéristiques spectrales ; il s’agit d’un « appariement spectral ». Il se peut aussi que deux éprouvettes de couleur n’ayant pas la même courbe de réflexion spectrale présentent la même couleur sous une source lumineuse donnée, mais pas sous une autre source lumineuse de caractéristiques spectrales différentes ; il s’agit alors d’un « appariement métamérique ».
« L’indice de métamérisme » constitue une description quantitative du métamérisme.
L’indice de métamérisme a une valeur limitée lorsque ΔE (différence de couleur mesurée par des instruments pour un illuminant donné) est > 0,5. L’indice de métamérisme ne permet pas de déterminer la différence de couleur absolue ou la constance de couleur d’une éprouvette donnée si l’illuminant change.
La différence de couleur sous l’illuminant de référence doit être mesurée en coordonnées chromatiques L*, a* et b*.
Cette méthode ne s’applique pas aux revêtements organiques fluorescents et/ou multicolores, nacrés ou métalliques.
Cette méthode n’a pas pour objet d’établir une référence ou de déterminer l’amplitude d’une différence de couleur acceptable.
Deux méthodes sont décrites dans le présent document :
a)   la mesure de la différence de couleur au moyen d’un colorimètre trichromatique ;
b)   la mesure de la différence de couleur au moyen d’un spectrophotomètre ou d’un instrument équivalent.
Il est conseillé de prendre des précautions, par exemple lors de la mesure de :
—   surfaces texturées ;
—   revêtements fluorescents ;
—   revêtements métamères ;
—   revêtements multicolores, nacrés, métalliques ou à effet de couleur spécial.

Prevlečene kovine, ki se navijajo - Preskusne metode - 3. del: Barvna razlika in metamerija - Primerjava z merilnim instrumentom

General Information

• Status: Not Published
• Public Enquiry End Date: 02-Oct-2023
• ICS: 17.180.20 - Colours and measurement of light
• ICS: 25.220.60 - Organic coatings
• Technical Committee: IBLP - Paints and varnishes
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 09-Jun-2023
• Due Date: 27-Oct-2023
• Ref Project: prEN 13523-3 - Coil coated metals - Test methods - Part 3: Colour difference and metamerism - Instrumental comparison

Relations

• Revises: SIST EN 13523-3:2021 - Coil coated metals - Test methods - Part 3: Colour difference and metamerism - Instrumental comparison
• Effective Date: 01-Sep-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 13523-3:2023
01-september-2023
Prevlečene kovine, ki se navijajo - Preskusne metode - 3. del: Barvna razlika in
metamerija - Primerjava z merilnim instrumentom
Coil coated metals - Test methods - Part 3: Colour difference and metamerism -
Instrumental comparison
Bandbeschichtete Metalle - Prüfverfahren - Teil 3: Farbabstand und Metamerie -
Farbmetrischer Vergleich
Tôles prélaquées - Méthodes d'essai - Partie 3 : Différence de couleur et métamérisme -
Comparaison au moyen d'instruments
Ta slovenski standard je istoveten z: prEN 13523-3
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
25.220.60 Organske prevleke Organic coatings
oSIST prEN 13523-3:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 13523-3:2023

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oSIST prEN 13523-3:2023


DRAFT
EUROPEAN STANDARD
prEN 13523-3
NORME EUROPÉENNE

EUROPÄISCHE NORM

July 2023
ICS 25.220.60 Will supersede EN 13523-3:2021
English Version

Coil coated metals - Test methods - Part 3: Colour
difference and metamerism - Instrumental comparison
Tôles prélaquées - Méthodes d'essai - Partie 3 : Bandbeschichtete Metalle - Prüfverfahren - Teil 3:
Différence de couleur et métamérisme - Comparaison Farbabstand und Metamerie - Farbmetrischer
au moyen d'instruments Vergleich
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 139.

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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13523-3:2023 E
worldwide for CEN national Members.

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oSIST prEN 13523-3:2023
prEN 13523-3:2023 (E)
Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Principle . 6
4.1 Colour coordinates . 6
4.2 Metamerism index . 7
5 Apparatus . 7
6 Sampling . 7
7 Test specimens . 7
8 Procedure . 7
8.1 Calibration . 7
8.2 Measurement . 7
9 Expression of results . 8
10 Accuracy . 9
11 Test report . 10
Bibliography . 11
2

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oSIST prEN 13523-3:2023
prEN 13523-3:2023 (E)
European foreword
This document (prEN 13523-3:2023) has been prepared by Technical Committee CEN/TC 139 “Paints
and varnishes”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13523-3:2021.
In comparison with the previous edition, the following technical modifications have been made:
a) calculating colour differences according to the CIEDE2000 formula has been added;
b) the text has been editorially revised and the normative references have been updated.
The EN 13523 series, Coil coated metals — Test methods, consists of the following parts:
— Part 0: General introduction
— Part 1: Film thickness
— Part 2: Gloss
— Part 3: Colour difference and metamerism — Instrumental comparison
— Part 4: Pencil hardness
— Part 5: Resistance to rapid deformation (impact test)
— Part 6: Adhesion after indentation (cupping test)
— Part 7: Resistance to cracking on bending (T-bend test)
— Part 8: Resistance to salt spray (fog)
— Part 9: Resistance to water immersion
— Part 10: Resistance to fluorescent UV radiation and water condensation
— Part 11: Resistance to solvents (rubbing test)
— Part 12: Resistance to scratching
— Part 13: Resistance to accelerated ageing by the use of heat
— Part 14: Chalking (Helmen method)
— Part 16: Resistance to abrasion
— Part 17: Adhesion of strippable films
— Part 18: Resistance to staining
— Part 19: Panel design and method of atmospheric exposure testing
3

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oSIST prEN 13523-3:2023
prEN 13523-3:2023 (E)
— Part 20: Foam adhesion
— Part 21: Evaluation of outdoor exposed panels
— Part 22: Colour difference — Visual comparison
— Part 23: Resistance to humid atmospheres containing sulfur dioxide
— Part 24: Resistance to blocking and pressure marking
— Part 25: Resistance to humidity
— Part 26: Resistance to condensation of water
— Part 27: Resistance to humid poultice (Cataplasm test)
— Part 29: Resistance to environmental soiling (Dirt pick-up and striping)
4

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oSIST prEN 13523-3:2023
prEN 13523-3:2023 (E)
1 Scope
*
This document specifies procedures for determining the instrumental colour difference (CIELAB ∆E
Lab
or ∆E ) of an organic coating on a metallic substrate compared to another one used as a reference
00
(usually called reference) and the metamerism depending on the illuminant.
When two colour specimens have identical spectral reflectance curves, they are matching under any
illuminant irrespective of its spectral characteristics. This is termed a “spectral match”. It is also possible
for two colour specimens having different spectral reflectance curves to match visually under a given
light source but not to match under another light source with different spectral characteristics; such
matches are termed “metameric”.
One quantitative description of metamerism is the so-called “metamerism index”.
Information on the metamerism index is of limited value where ΔE (instrumental colour difference for a
given illuminant) is > 0,5. The metamerism index is not suited for determining the absolute colour
difference or colour consistency of a given specimen at change of illuminant.
The colour difference under the reference illuminant is to be measured in colour coordinates L*, a* and
b*.
Excluded from this method are organic coatings producing fluorescence and/or which are multicoloured,
pearlescent or metallic.
Establishing a reference as well as the magnitude of an acceptable colour difference are not covered by
this method.
Two methods are given in this document:
a) instrumental colour difference measurement using a tristimulus colourimeter;
b) instrumental colour difference measurement using a spectrophotometer or equivalent.
It is advised that care is taken when measuring e.g.
— textured surfaces;
— fluorescent coatings;
— metameric coatings;
— multi-coloured, pearlescent, metallic or special colour effect coatings.
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) appl
...