ISO 5631-1:2009

Paper and board — Determination of colour by diffuse reflectance — Part 1: Indoor daylight conditions (C/2 degrees)

ISO 5631-1:2009 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. ISO 5631-1:2009 is not applicable to coloured papers or boards which incorporate fluorescent dyes or pigments. It may be used to determine the colour of papers or boards which contain fluorescent whitening agents provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard provided by an ISO/TC 6 authorized laboratory, as described in ISO 2470-1.

Papier et carton — Détermination de la couleur par réflectance diffuse — Partie 1: Conditions d'éclairage intérieur de jour (C/2 degrés)

L'ISO 5631-1:2009 spécifie une méthode de mesurage de la couleur des papiers et cartons par réflectance diffuse avec élimination du brillant spéculaire. L'ISO 5631-1:2009 n'est pas applicable aux papiers et cartons colorés qui contiennent des pigments ou des colorants fluorescents. Elle peut être utilisée pour déterminer la couleur des papiers et cartons contenant des agents d'azurage fluorescents, sous réserve que la proportion d'UV de l'éclairage sur l'éprouvette ait été ajustée de manière à être conforme à celle de l'illuminant normalisé CIE C, à l'aide d'un étalon de référence fluorescent fourni par un laboratoire agréé par l'ISO/TC 6, comme décrit dans l'ISO 2470‑1.

Papir, karton in lepenka - Določanje barve z razpršeno odsevnostjo - 1. del: Pogoji osvetlitve v prostoru (C/2°)

Ta del ISO 5631 določa metodo za merjenje barve papirja, kartona in lepenke z metodo razpršene
odsevnosti, z odpravo sijaja.
Ta del ISO 5631 se ne uporablja za obarvane papirje, kartone ali lepenke, ki vsebujejo fluorescenčna barvila ali pigmente. Uporablja se lahko za določanje barve papirjev, kartonov ali lepenk, ki vsebujejo fluorescenčna belilna sredstva, pod pogojem, da je bila vsebnost UV sevanja na preskušanca prilagojena tako, da ustreza vrsti svetlobe CIE C, z uporabo referenčnega standarda za fluorescenco, ki ga zagotavlja laboratorij, pooblaščen po ISO/TC 6, kot je opisano v ISO 2470-1.

General Information

• Status: Withdrawn
• Publication Date: 12-Oct-2009
• Withdrawal Date: 12-Oct-2009
• ICS: 85.060 - Paper and board
• Technical Committee: ISO/TC 6 - Paper, board and pulps
• Drafting Committee: ISO/TC 6/WG 3 - Optical properties
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 26-Oct-2015
• Ref Project: SIST ISO 5631-1:2011 - Paper and board -- Determination of colour by diffuse reflectance -- Part 1: Indoor daylight conditions (C/2 degrees)

Relations

• Revised: ISO 5631-1:2015 - Paper and board — Determination of colour by diffuse reflectance — Part 1: Indoor daylight conditions (C/2 degrees)
• Effective Date: 17-May-2014
• Revises: ISO 5631:2000 - Paper and board — Determination of colour (C/2 degrees) — Diffuse reflectance method
• Effective Date: 15-Apr-2008
• Revised: SIST ISO 5631:2004 - Paper and board -- Determination of colour (C/2 degrees) -- Diffuse reflectance method
• Effective Date: 14-Aug-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 5631-1
First edition
2009-10-15

Paper and board — Determination of
colour by diffuse reflectance —
Part 1:
Indoor daylight conditions (C/2°)
Papier et carton — Détermination de la couleur par réflectance
diffuse —
Partie 1: Conditions d'éclairage intérieur de jour (C/2°)




Reference number
ISO 5631-1:2009(E)
©
ISO 2009

---------------------- Page: 1 ----------------------
ISO 5631-1:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland

ii © ISO 2009 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 5631-1:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Principle.3
5 Apparatus.3
6 Sampling and conditioning .4
7 Preparation of test pieces.4
8 Procedure.4
9 Calculation .5
9.1 CIE tristimulus values.5
9.2 CIELAB coordinates.5
9.3 Dispersion of the results .5
10 Expression of results.6
11 Precision.6
12 Test report.6
Annex A (normative) Calculation of tristimulus values .7
Bibliography.10

© ISO 2009 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 5631-1:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 5631-1 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps.
This first edition of ISO 5631-1 cancels and replaces ISO 5631:2000, which has been technically revised.
ISO 5631 consists of the following parts, under the general title Paper and board — Determination of colour by
diffuse reflectance:
⎯ Part 1: Indoor daylight conditions (C/2°)
⎯ Part 2: Outdoor daylight conditions (D65/10°)
⎯ Part 3: Indoor illumination conditions (D50/2°)
iv © ISO 2009 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 5631-1:2009(E)
Introduction
The colour of an object can be uniquely characterized by means of a triplet of colour coordinates such as the
1964 CIE tristimulus values or the CIELAB 1976 L*, a*, b* coordinates.
Apart from the optical properties of the sample, the values of such coordinates depend upon the conditions of
measurement, particularly the spectral and geometric characteristics of the instrument used. This part of
ISO 5631 should therefore be read in conjunction with ISO 2469.
This part of ISO 5631 describes the measurement and description of colour in terms of the CIE illuminant C
and the CIE 1931 (2°) standard observer. The other parts of this International Standard describe
measurements and calculations carried out in an analogous manner using either the CIE standard illuminant
D65 and the CIE 1964 (10°) standard observer or the CIE illuminant D50 and the CIE 1931 (2°) standard
observer.
The choice of illuminant conditions is important when determining the colour coordinates of white papers
containing a fluorescent whitening agent. In ISO 5631-2, the UV content of the illumination is much higher,
approximating UV levels encountered in outdoor viewing conditions.
ISO 5631-3 describes the measurement and description of colour in terms of the CIE standard illuminant D50
and the CIE 1931 (2°) standard observer. This method is especially applicable to graphic arts situations since
these illuminant/observer conditions are used within the graphic arts industry.

© ISO 2009 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 5631-1:2009(E)

Paper and board — Determination of colour by diffuse
reflectance —
Part 1:
Indoor daylight conditions (C/2°)
1 Scope
This part of ISO 5631 specifies a method for measuring the colour of paper and board by the diffuse
reflectance method with the elimination of specular gloss.
This part of ISO 5631 is not applicable to coloured papers or boards which incorporate fluorescent dyes or
pigments. It may be used to determine the colour of papers or boards which contain fluorescent whitening
agents provided the UV content of the illumination on the test piece has been adjusted to conform to that in
the CIE illuminant C, using a fluorescent reference standard provided by an ISO/TC 6 authorized laboratory,
as described in ISO 2470-1.
2 Normative references
The following referenced documents are indispensable for the application 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.
ISO 186, Paper and board — Sampling to determine average quality
ISO 2469:2007, Paper, board and pulps — Measurement of diffuse radiance factor
ISO 2470-1, Paper, board and pulps — Measurement of diffuse blue reflectance factor — Part 1: Indoor
daylight conditions (ISO brightness)
CIE Publication 15:2004, Colorimetry, 3rd ed.
ASTM E308-06, Standard Practice for Computing the Colors of Objects by Using the CIE System
© ISO 2009 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 5631-1:2009(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
radiance factor
β
ratio of the radiance of a surface element of a body in the direction delimited by a given cone, with its apex at
the surface element, to that of the perfect reflecting diffuser under the same conditions of illumination
NOTE For fluorescent (luminescent) materials, the total radiance factor, β, is the sum of two portions, the reflected
radiance factor, β , and the luminescent radiance factor, β , so that
S L
β = β β
S + L
For non-fluorescent materials, the reflected radiance factor, β , is numerically equal to the reflectance factor, R.
S
3.2
reflectance factor
R
ratio of the radiation reflected by a surface element of a body in the direction delimited by a given cone, with
its apex at the surface element, to that of the perfect reflecting diffuser under the same conditions of
illumination
NOTE 1 The ratio is often expressed as a percentage.
NOTE 2 The reflectance factor is influenced by the backing if the body is translucent.
NOTE 3 The reflectance factor of a non-opaque sheet is dependent on the background and is not a material property.
3.3
intrinsic radiance [reflectance] factor
R
∞
radiance [reflectance] factor of a layer or pad of material thick enough to be opaque, such that increasing the
thickness of the pad by doubling the number of sheets results in no change in the measured radiance
[reflectance] factor
NOTE The ratio is often expressed as a percentage.
3.4
tristimulus values
X, Y, Z
amounts of the three reference colour stimuli, in a given chromatic system, required to match the stimulus
considered
NOTE 1 In this part of ISO 5631, the CIE 1931 (2°) standard observer and the CIE illuminant C are used to define the
trichromatic system.
NOTE 2 No subscript is applied to conform to the CIE convention that tristimulus values have no subscript when the
CIE 1931 (2°) standard observer is used [the subscript 10 is applied for tristimulus values that are obtained using the
CIE 1964 (10º) standard observer].
2 © ISO 2009 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 5631-1:2009(E)
3.5
CIELAB colour space
three-dimensional, approximately uniform colour space, produced by plotting, in rectangular coordinates
L*, a*, b*, quantities defined by the equations given in Clause 9
NOTE The quantity L* is a measure of the lightness of the test piece, where L* = 0 corresponds to black and L* = 100
is defined by the perfect reflecting diffuser. Visually, the quantities a* and b* represent respectively the red-green and
yellow-blue axes in colour space, such that
+a* is a measure of the degree of redness of the test piece,
−a* is a measure of the degree of greenness of the test piece,
+b* is a measure of the degree of yellowness of the test piece,
−b* is a measure of the degree of blueness of the test piece.
If both a* and b* are equal to zero, the test piece is grey.
4 Principle
The light reflected from a sample under specified conditions is analysed either by a tristimulus-filter
colorimeter or by an abridged spectrophotometer, and the colour coordinates are then calculated for C/2°
conditions.
5 Apparatus
5.1 Reflectometer
5.1.1 Reflectometer, having the geometric, spectral and photometric characteristics described in ISO 2469,
and calibrated in accordance with the provisions of ISO 2469.
If materials containing fluorescent whitening agents are to be measured, the reflectometer shall be equipped
with a radiation source having an adequate UV content control adjusted to a UV condition corresponding to
the C illuminant by the use of a reference standard, as described in ISO 2470-1.
5.1.2 In the case of a filter reflectometer, a set of filters that, in conjunction with the optical characteristics of
the basic instrument, give overall responses equivalent to the CIE tristimulus values X, Y and Z of the
CIE 1931 standard colorimetric system of the test piece evaluated for the CIE illuminant C.
In the case of a filter reflectometer, the radiation falling upon the test pie
...

SLOVENSKI STANDARD
SIST ISO 5631-1:2011
01-maj-2011
3DSLUNDUWRQLQOHSHQND'RORþDQMHEDUYH]UD]SUãHQRRGVHYQRVWMRGHO3RJRML
RVYHWOLWYHYSURVWRUX&ƒ
Paper and board -- Determination of colour by diffuse reflectance -- Part 1: Indoor
daylight conditions (C/2 degrees)
Papier et carton -- Détermination de la couleur par réflectance diffuse -- Partie 1:
Conditions d'éclairage intérieur de jour (C/2 degrés)
Ta slovenski standard je istoveten z: ISO 5631-1:2009
ICS:
85.060 Papir, karton in lepenka Paper and board
SIST ISO 5631-1:2011 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 5631-1:2011

---------------------- Page: 2 ----------------------

SIST ISO 5631-1:2011

INTERNATIONAL ISO
STANDARD 5631-1
First edition
2009-10-15

Paper and board — Determination of
colour by diffuse reflectance —
Part 1:
Indoor daylight conditions (C/2°)
Papier et carton — Détermination de la couleur par réflectance
diffuse —
Partie 1: Conditions d'éclairage intérieur de jour (C/2°)




Reference number
ISO 5631-1:2009(E)
©
ISO 2009

---------------------- Page: 3 ----------------------

SIST ISO 5631-1:2011
ISO 5631-1:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland

ii © ISO 2009 – All rights reserved

---------------------- Page: 4 ----------------------

SIST ISO 5631-1:2011
ISO 5631-1:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Principle.3
5 Apparatus.3
6 Sampling and conditioning .4
7 Preparation of test pieces.4
8 Procedure.4
9 Calculation .5
9.1 CIE tristimulus values.5
9.2 CIELAB coordinates.5
9.3 Dispersion of the results .5
10 Expression of results.6
11 Precision.6
12 Test report.6
Annex A (normative) Calculation of tristimulus values .7
Bibliography.10

© ISO 2009 – All rights reserved iii

---------------------- Page: 5 ----------------------

SIST ISO 5631-1:2011
ISO 5631-1:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 5631-1 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps.
This first edition of ISO 5631-1 cancels and replaces ISO 5631:2000, which has been technically revised.
ISO 5631 consists of the following parts, under the general title Paper and board — Determination of colour by
diffuse reflectance:
⎯ Part 1: Indoor daylight conditions (C/2°)
⎯ Part 2: Outdoor daylight conditions (D65/10°)
⎯ Part 3: Indoor illumination conditions (D50/2°)
iv © ISO 2009 – All rights reserved

---------------------- Page: 6 ----------------------

SIST ISO 5631-1:2011
ISO 5631-1:2009(E)
Introduction
The colour of an object can be uniquely characterized by means of a triplet of colour coordinates such as the
1964 CIE tristimulus values or the CIELAB 1976 L*, a*, b* coordinates.
Apart from the optical properties of the sample, the values of such coordinates depend upon the conditions of
measurement, particularly the spectral and geometric characteristics of the instrument used. This part of
ISO 5631 should therefore be read in conjunction with ISO 2469.
This part of ISO 5631 describes the measurement and description of colour in terms of the CIE illuminant C
and the CIE 1931 (2°) standard observer. The other parts of this International Standard describe
measurements and calculations carried out in an analogous manner using either the CIE standard illuminant
D65 and the CIE 1964 (10°) standard observer or the CIE illuminant D50 and the CIE 1931 (2°) standard
observer.
The choice of illuminant conditions is important when determining the colour coordinates of white papers
containing a fluorescent whitening agent. In ISO 5631-2, the UV content of the illumination is much higher,
approximating UV levels encountered in outdoor viewing conditions.
ISO 5631-3 describes the measurement and description of colour in terms of the CIE standard illuminant D50
and the CIE 1931 (2°) standard observer. This method is especially applicable to graphic arts situations since
these illuminant/observer conditions are used within the graphic arts industry.

© ISO 2009 – All rights reserved v

---------------------- Page: 7 ----------------------

SIST ISO 5631-1:2011

---------------------- Page: 8 ----------------------

SIST ISO 5631-1:2011
INTERNATIONAL STANDARD ISO 5631-1:2009(E)

Paper and board — Determination of colour by diffuse
reflectance —
Part 1:
Indoor daylight conditions (C/2°)
1 Scope
This part of ISO 5631 specifies a method for measuring the colour of paper and board by the diffuse
reflectance method with the elimination of specular gloss.
This part of ISO 5631 is not applicable to coloured papers or boards which incorporate fluorescent dyes or
pigments. It may be used to determine the colour of papers or boards which contain fluorescent whitening
agents provided the UV content of the illumination on the test piece has been adjusted to conform to that in
the CIE illuminant C, using a fluorescent reference standard provided by an ISO/TC 6 authorized laboratory,
as described in ISO 2470-1.
2 Normative references
The following referenced documents are indispensable for the application 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.
ISO 186, Paper and board — Sampling to determine average quality
ISO 2469:2007, Paper, board and pulps — Measurement of diffuse radiance factor
ISO 2470-1, Paper, board and pulps — Measurement of diffuse blue reflectance factor — Part 1: Indoor
daylight conditions (ISO brightness)
CIE Publication 15:2004, Colorimetry, 3rd ed.
ASTM E308-06, Standard Practice for Computing the Colors of Objects by Using the CIE System
© ISO 2009 – All rights reserved 1

---------------------- Page: 9 ----------------------

SIST ISO 5631-1:2011
ISO 5631-1:2009(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
radiance factor
β
ratio of the radiance of a surface element of a body in the direction delimited by a given cone, with its apex at
the surface element, to that of the perfect reflecting diffuser under the same conditions of illumination
NOTE For fluorescent (luminescent) materials, the total radiance factor, β, is the sum of two portions, the reflected
radiance factor, β , and the luminescent radiance factor, β , so that
S L
β = β β
S + L
For non-fluorescent materials, the reflected radiance factor, β , is numerically equal to the reflectance factor, R.
S
3.2
reflectance factor
R
ratio of the radiation reflected by a surface element of a body in the direction delimited by a given cone, with
its apex at the surface element, to that of the perfect reflecting diffuser under the same conditions of
illumination
NOTE 1 The ratio is often expressed as a percentage.
NOTE 2 The reflectance factor is influenced by the backing if the body is translucent.
NOTE 3 The reflectance factor of a non-opaque sheet is dependent on the background and is not a material property.
3.3
intrinsic radiance [reflectance] factor
R
∞
radiance [reflectance] factor of a layer or pad of material thick enough to be opaque, such that increasing the
thickness of the pad by doubling the number of sheets results in no change in the measured radiance
[reflectance] factor
NOTE The ratio is often expressed as a percentage.
3.4
tristimulus values
X, Y, Z
amounts of the three reference colour stimuli, in a given chromatic system, required to match the stimulus
considered
NOTE 1 In this part of ISO 5631, the CIE 1931 (2°) standard observer and the CIE illuminant C are used to define the
trichromatic system.
NOTE 2 No subscript is applied to conform to the CIE convention that tristimulus values have no subscript when the
CIE 1931 (2°) standard observer is used [the subscript 10 is applied for tristimulus values that are obtained using the
CIE 1964 (10º) standard observer].
2 © ISO 2009 – All rights reserved

---------------------- Page: 10 ----------------------

SIST ISO 5631-1:2011
ISO 5631-1:2009(E)
3.5
CIELAB colour space
three-dimensional, approximately uniform colour space, produced by plotting, in rectangular coordinates
L*, a*, b*, quantities defined by the equations given in Clause 9
NOTE The quantity L* is a measure of the lightness of the test piece, where L* = 0 corresponds to black and L* = 100
is defined by the perfect reflecting diffuser. Visually, the quantities a* and b* represent respectively the red-green and
yellow-blue axes in colour space, such that
+a* is a measure of the degree of redness of the test piece,
−a* is a measure of the degree of greenness of the test piece,
+b* is a measure of the degree of yellowness of the test piece,
−b* is a measure of the degree of blueness of the test piece.
If both a* and b* are equal to zero, the test piece is grey.
4 Principle
The light reflected from a sample under specified conditions is analysed either by a tristimulus-filter
colorimeter or by an abridged spectrophotometer, and the colour coordinates are then calculated for C/2°
conditions.
5 Apparatus
5.1 Reflectometer
5.1.1 Reflectometer, having the geometric, spectral and photometric characteristics described in ISO 2469,
and calibrated in accordance with the provisions of ISO 2469.
If materials containing fluorescent whitening agents are to be measured, the reflectometer shall be equipped
with a radiation source having an adequate UV content co
...

NORME ISO
INTERNATIONALE 5631-1
Première édition
2009-10-15


Papier et carton — Détermination de la
couleur par réflectance diffuse —
Partie 1:
Conditions d'éclairage intérieur de jour
(C/2°)
Paper and board — Determination of colour by diffuse reflectance —
Part 1: Indoor daylight conditions (C/2°)




Numéro de référence
ISO 5631-1:2009(F)
©
ISO 2009

---------------------- Page: 1 ----------------------
ISO 5631-1:2009(F)
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DOCUMENT PROTÉGÉ PAR COPYRIGHT


©  ISO 2009
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit
de l'ISO à l'adresse ci-après ou du comité membre de l'ISO dans le pays du demandeur.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Publié en Suisse

ii © ISO 2009 – Tous droits réservés

---------------------- Page: 2 ----------------------
ISO 5631-1:2009(F)
Sommaire Page
Avant-propos .iv
Introduction.v
1 Domaine d'application .1
2 Références normatives.1
3 Termes et définitions .2
4 Principe.3
5 Appareillage .3
6 Échantillonnage et conditionnement .4
7 Préparation des éprouvettes.4
8 Mode opératoire.4
9 Calculs.5
9.1 Composantes trichromatiques CIE .5
9.2 Coordonnées CIELAB .5
9.3 Dispersion des résultats.6
10 Expression des résultats.6
11 Fidélité .6
12 Rapport d'essai.7
Annexe A (normative) Calcul des composantes trichromatiques.8
Bibliographie.11

© ISO 2009 – Tous droits réservés iii

---------------------- Page: 3 ----------------------
ISO 5631-1:2009(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 5631-1 a été élaborée par le comité technique ISO/TC 6, Papiers, cartons et pâtes.
Cette première édition de l’ISO 5631-1 annule et remplace l’ISO 5631 :2000 qui a fait l’objet d’une révision
technique.
L'ISO 5631 comprend les parties suivantes, présentées sous le titre général Papier et carton — Détermination
de la couleur par réflectance diffuse:
⎯ Partie 1: Conditions d'éclairage intérieur de jour (C/2°)
⎯ Partie 2: Conditions de lumière du jour extérieure (D65/10°)
⎯ Partie 3: Conditions d'éclairage intérieur (D50/2°)
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ISO 5631-1:2009(F)
Introduction
La couleur d'un objet peut être uniquement caractérisée au moyen d'un ensemble de trois coordonnées de
couleur comme les coordonnées trichromatiques CIE 1964 ou les coordonnées CIELAB 1976 L*, a*, b*.
Outre les propriétés optiques de l'échantillon, les valeurs de ces coordonnées dépendent des conditions de
mesurage, notamment des caractéristiques spectrales et géométriques de l'appareil utilisé. Par conséquent, il
convient de lire la présente partie de l'ISO 5631 conjointement avec l'ISO 2469.
La présente partie de l'ISO 5631 décrit le mesurage et la description de la couleur en terme d'illuminant CIE C
et d'observateur de référence CIE 1931 (2°). Les autres parties de la présente Norme internationale décrivent
les mesurages et les calculs effectués de manière analogue en utilisant soit l'illuminant normalisé CIE D65 et
l'observateur de référence CIE 1964 (10°), soit l'illuminant CIE D50 et l'observateur de référence
CIE 1931 (2°).
Le choix de l'illuminant est important lors de la détermination des coordonnées colorimétriques des papiers
blancs contenant un agent d'azurage fluorescent. Dans l'ISO 5631-2, la proportion d'UV dans l'éclairage est
très supérieure, avoisinant les niveaux d'UV rencontrés lors d'une exposition à l'extérieur.
L'ISO 5631-3 détaille le mesurage et la description de la couleur en termes d'illuminant normalisé CIE D50 et
d'observateur de référence CIE 1931 (2°). Cette méthode convient particulièrement bien au domaine des arts
graphiques car ces conditions d'illuminant et d'observateur sont utilisées dans l'industrie des arts graphiques.

© ISO 2009 – Tous droits réservés v

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NORME INTERNATIONALE ISO 5631-1:2009(F)

Papier et carton — Détermination de la couleur par réflectance
diffuse —
Partie 1:
Conditions d'éclairage intérieur de jour (C/2°)
1 Domaine d'application
La présente partie de l'ISO 5631 spécifie une méthode de mesurage de la couleur des papiers et cartons par
réflectance diffuse avec élimination du brillant spéculaire.
La présente partie de l'ISO 5631 n'est pas applicable aux papiers et cartons colorés qui contiennent des
pigments ou des colorants fluorescents. Elle peut être utilisée pour déterminer la couleur des papiers et
cartons contenant des agents d'azurage fluorescents, sous réserve que la proportion d'UV de l'éclairage sur
l'éprouvette ait été ajustée de manière à être conforme à celle de l'illuminant normalisé CIE C, à l'aide d'un
étalon de référence fluorescent fourni par un laboratoire agréé par l'ISO/TC 6, comme décrit dans
l'ISO 2470-1.
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence s'applique (y compris les éventuels amendements).
ISO 186, Papier et carton — Échantillonnage pour déterminer la qualité moyenne
ISO 2469:2007, Papier, carton et pâtes — Mesurage du facteur de luminance énergétique diffuse
ISO 2470-1, Papier, carton et pâtes — Mesurage du facteur de réflectance diffuse dans le bleu — Partie 1:
Conditions d'éclairage intérieur de jour (degré de blancheur ISO)
e
Publication CIE 15:2004, Colorimétrie, 3 éd.
ASTM E308-06, Standard Practice for Computing the Colors of Objects by Using the CIE System
© ISO 2009 – Tous droits réservés 1

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ISO 5631-1:2009(F)
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s'appliquent.
3.1
facteur de luminance énergétique
β
rapport de la luminance énergétique en un élément de surface d'un corps dans la direction délimitée par un
cône donné dont le sommet se trouve au niveau de l'élément de surface, à la luminance énergétique du
diffuseur parfait par réflexion, dans les mêmes conditions d'éclairage
NOTE Pour les matériaux fluorescents (luminescents), le facteur de luminance énergétique total, β, est la somme de
deux grandeurs, le facteur de luminance énergétique par réflexion, β , et le facteur de luminance énergétique par
S
luminescence, β , de sorte que
L
β = β + β
S L
Pour les matériaux non fluorescents, la valeur du facteur de luminance énergétique par réflexion, β , est numériquement
S
égal à celle du facteur de réflectance, R.
3.2
facteur de réflectance
R
rapport du rayonnement réfléchi par un élément de surface d'un corps dans la direction délimitée par un cône
donné dont le sommet se trouve au niveau de l'élément de surface, au rayonnement réfléchi par le diffuseur
parfait par réflexion, dans les mêmes conditions d'éclairage
NOTE 1 Ce rapport est souvent exprimé en pourcentage.
NOTE 2 Si le corps est translucide, le facteur de réflectance est influencé par le support.
NOTE 3 Le facteur de réflectance d'une feuille non opaque dépend du fond et n'est pas une propriété du matériau.
3.3
facteur de luminance [réflectance] énergétique intrinsèque
R
∞
facteur de luminance [réflectance] énergétique d'une couche ou d'une liasse de matériau suffisamment
épaisse pour être opaque, c'est-à-dire telle que l'augmentation de l'épaisseur de la liasse, par doublement du
nombre de feuilles la constituant, n'engendre aucune modification du facteur de luminance [réflectance]
énergétique mesuré
NOTE Ce rapport est souvent exprimé en pourcentage.
3.4
composantes trichromatiques
X, Y, Z
quantités des trois stimuli de couleur de référence, dans un système trichromatique donné, nécessaires pour
correspondre à la couleur du stimulus considéré
NOTE 1 Dans la présente partie de l'ISO 5631, l'observateur de référence CIE 1931 (2°) et l'illuminant CIE C sont
utilisés pour définir le système trichromatique.
NOTE 2 Aucun indice n'est utilisé pour respecter la convention CIE selon laquelle les composantes trichromatiques ne
comportent pas d'indice lorsque l'on utilise l'observateur normalisé CIE 1931 (2°) [l'indice 10 est utilisé pour les
composantes trichromatiques obtenues lorsque l'on utilise l'observateur normalisé CIE 1964 (10°)].
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ISO 5631-1:2009(F)
3.5
espace chromatique CIELAB
espace chromatique à trois dimensions approximativement uniforme, obtenu en portant en coordonnées
rectangulaires les grandeurs L*, a*, b* définies par les équations données dans l'Article 9
NOTE La grandeur L* est une mesure de la clarté de l'éprouvette, où L* = 0 correspond au noir et L* = 100 est défini
par le diffuseur parfait par réflexion. Visuellement, les grandeurs a* et b* représentent respectivement les axes du
rouge-vert et jaune-bleu de l'espace chromatique, de sorte que
+a* est une mesure de la composante monochromatique rouge de l'éprouvette,
−a* est une mesure de la composante monochromatique verte de l'éprouvette,
+b* est une mesure de la composante monochromatique jaune de l'éprouvette,
−b* est une mesure de la composante monochromatique bleue de l'éprouvette.
Si a* et b* sont tous deux égaux à zéro, l'éprouvette est grise.
4 Principe
La lumière réfléchie par un échantillon dans des conditions spécifiées est analysée soit au moyen d'un
colorimètre à filtre trichromatique, soit à l'aide d'un spectrophotomètre continu, et les coordonnées
chromatiques sont calculées pour les conditions C/2°.
5 Appareillage
5.1 Réflectomètre
5.1.1 Réflectomètre, ayant les caractéristiques géométriques, spectrales et photométriques décrites dans
l'ISO 2469 et étalonné conformément aux dispositions de l'ISO 2469.
Si des matériaux contenant des agents d'azurage fluorescents doivent être mesurés, le réflectomètre doit être
équipé d'une source de rayonnement avec un contrôle adéquat de la proportion d'UV réglée à un niveau
correspondant à l'illuminant C au moyen d'un étalon de référence, comme décrit dans l'ISO 2470-1.
5.1.2 Ensemble de filtres, en cas d'utilisation d'un réflectomètre à filtre, qui conjointement aux
caractéristiques optiques de l'appareil de base, donnent des réponses globales équivalant aux composantes
trichromatiques CIE X, Y et Z du système de référence colorimétrique CIE 1931 de l'éprouvette évaluée pour
l'illuminant CIE C.
En cas d'utilisation d'un réflectomètre à filtres, le rayonnement tombant sur l'éprouvette doit contenir une
proportion d'UV correspondant à celle de l'illuminant CIE C.
5.1.3 Fonction permettant de calculer les compo
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Papier et carton -- Détermination de la couleur par réflectance diffuse -- Partie 1: Conditions d'éclairage intérieur de jour (C/2 degrés)Paper and board -- Determination of colour by diffuse reflectance -- Part 1: Indoor daylight conditions (C/2 degrees)85.060Papir, karton in lepenkaPaper and boardICS:Ta slovenski standard je istoveten z:ISO 5631-1:2009oSIST ISO 5631-1:2011en01-marec-2011oSIST ISO 5631-1:2011SLOVENSKI
STANDARD



oSIST ISO 5631-1:2011



Reference numberISO 5631-1:2009(E)© ISO 2009
INTERNATIONAL STANDARD ISO5631-1First edition2009-10-15Paper and board — Determination of colour by diffuse reflectance — Part 1: Indoor daylight conditions (C/2°) Papier et carton — Détermination de la couleur par réflectance diffuse — Partie 1: Conditions d'éclairage intérieur de jour (C/2°)
oSIST ISO 5631-1:2011



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© ISO 2009 – All rights reserved
oSIST ISO 5631-1:2011



ISO 5631-1:2009(E) © ISO 2009 – All rights reserved
iii Contents Page Foreword.iv Introduction.v 1 Scope.1 2 Normative references.1 3 Terms and definitions.2 4 Principle.3 5 Apparatus.3 6 Sampling and conditioning.4 7 Preparation of test pieces.4 8 Procedure.4 9 Calculation.5 9.1 CIE tristimulus values.5 9.2 CIELAB coordinates.5 9.3 Dispersion of the results.5 10 Expression of results.6 11 Precision.6 12 Test report.6 Annex A (normative)
Calculation of tristimulus values.7 Bibliography.10
oSIST ISO 5631-1:2011



ISO 5631-1:2009(E) iv
© ISO 2009 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 5631-1 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps. This first edition of ISO 5631-1 cancels and replaces ISO 5631:2000, which has been technically revised. ISO 5631 consists of the following parts, under the general title Paper and board — Determination of colour by diffuse reflectance: ⎯ Part 1: Indoor daylight conditions (C/2°) ⎯ Part 2: Outdoor daylight conditions (D65/10°) ⎯ Part 3: Indoor illumination conditions (D50/2°) oSIST ISO 5631-1:2011



ISO 5631-1:2009(E) © ISO 2009 – All rights reserved
v Introduction The colour of an object can be uniquely characterized by means of a triplet of colour coordinates such as the 1964 CIE tristimulus values or the CIELAB 1976 L*, a*, b* coordinates. Apart from the optical properties of the sample, the values of such coordinates depend upon the conditions of measurement, particularly the spectral and geometric characteristics of the instrument used. This part of ISO 5631 should therefore be read in conjunction with ISO 2469. This part of ISO 5631 describes the measurement and description of colour in terms of the CIE illuminant C and the CIE 1931 (2°) standard observer. The other parts of this International Standard describe measurements and calculations carried out in an analogous manner using either the CIE standard illuminant D65 and the CIE 1964 (10°) standard observer or the CIE illuminant D50 and the CIE 1931 (2°) standard observer. The choice of illuminant conditions is important when determining the colour coordinates of white papers containing a fluorescent whitening agent. In ISO 5631-2, the UV content of the illumination is much higher, approximating UV levels encountered in outdoor viewing conditions. ISO 5631-3 describes the measurement and description of colour in terms of the CIE standard illuminant D50 and the CIE 1931 (2°) standard observer. This method is especially applicable to graphic arts situations since these illuminant/observer conditions are used within the graphic arts industry.
oSIST ISO 5631-1:2011



oSIST ISO 5631-1:2011



INTERNATIONAL STANDARD ISO 5631-1:2009(E) © ISO 2009 – All rights reserved
1 Paper and board — Determination of colour by diffuse reflectance — Part 1: Indoor daylight conditions (C/2°) 1 Scope This part of ISO 5631 specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. This part of ISO 5631 is not applicable to coloured papers or boards which incorporate fluorescent dyes or pigments. It may be used to determine the colour of papers or boards which contain fluorescent whitening agents provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard provided by an ISO/TC 6 authorized laboratory, as described in ISO 2470-1. 2 Normative references The following referenced documents are indispensable for the application 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. ISO 186, Paper and board — Sampling to determine average quality ISO 2469:2007, Paper, board and pulps — Measurement of diffuse radiance factor ISO 2470-1, Paper, board and pulps — Measurement of diffuse blue reflectance factor — Part 1: Indoor daylight conditions (ISO brightness) CIE Publication 15:2004, Colorimetry, 3rd ed. ASTM E308-06, Standard Practice for Computing the Colors of Objects by Using the CIE System oSIST ISO 5631-1:2011



ISO 5631-1:2009(E) 2
© ISO 2009 – All rights reserved 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 radiance factor β ratio of the radiance of a surface element of a body in the direction delimited by a given cone, with its apex at the surface element, to that of the perfect reflecting diffuser under the same conditions of illumination NOTE For fluorescent (luminescent) materials, the total radiance factor, β, is the sum of two portions, the reflected radiance factor, βS, and the luminescent radiance factor, βL, so that β = βS + βL For non-fluorescent materials, the reflected radiance factor, βS, is numerically equal to the reflectance factor, R. 3.2 reflectance factor R ratio of the radiation reflected by a surface element of a body in the direction delimited by a given cone, with its apex at the surface element, to that of the perfect reflecting diffuser under the same conditions of illumination NOTE 1 The ratio is often expressed as a percentage. NOTE 2 The reflectance factor is influenced by the backing if the body is translucent. NOTE 3 The reflectance factor of a non-opaque sheet is dependent on the background and is not a material property. 3.3 intrinsic radiance [reflectance] factor R∞ radiance [reflectance] factor of a layer or pad of material thick enough to be opaque, such that increasing the thickness of the pad by doubling the number of sheets results in no change in the measured radiance [reflectance] factor NOTE The ratio is often expressed as a percentage. 3.4 tristimulus values X, Y, Z amounts of the three reference colour stimuli, in a given chromatic system, required to match the stimulus considered NOTE 1 In this part of ISO 5631, the CIE 1931 (2°) standard observer and the CIE illuminant C are used to define the trichromatic system. NOTE 2 No subscript is applied to conform to the CIE convention that tristimulus values have no subscript when the CIE 1931 (2°) standard observer is used [the subscript 10 is applied for tristimulus values that are obtained using the CIE 1964 (10º) standard observer]. oSIST ISO 5631-1:2011



ISO 5631-1:2009(E) © ISO 2009 – All rights reserved
3 3.5 CIELAB colour space three-dimensional, approximately uniform colour space, produced by plotting, in rectangular coordinates L*, a*, b*, quantities defined by the equations given in Clause 9 NOTE The quantity L* is a measure of the lightness of the test piece, where L* = 0 corresponds to black and L* = 100 is defined by the perfect reflecting diffuser. Visually, the quantities a* and b* represent respectively the red-green and yellow-blue axes in colour space, such that +a* is a measure of the degree of redness of the test piece, −a* is a measure of the degree of greenness of the test piece, +b* is a measure of the degree of yellowness of the test piece, −b* is a measure of the degree of blueness of the test piece. If both a* and b* are equal to zero, the test piece is grey. 4 Principle The light reflected from a sample under specified conditions is analysed either by a tristimulus-filter colorimeter or by an abridged spectrophotometer, and the colour coordinates are then calculated for C/2° conditions. 5 Apparatus 5.1 Reflectometer 5.1.1 Reflectometer, having the geometric, spectral and photometric characteristics described in ISO 2469, and calibrated in accordance with the provisions of ISO 2469. If materials containing fluorescent whitening agents are to be measured, the reflectometer shall be equipped with a radiation source having an
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