SIST ISO 11476:2011
Paper and board -- Determination of CIE whiteness, C/2 degrees (indoor illumination conditions)
Paper and board -- Determination of CIE whiteness, C/2 degrees (indoor illumination conditions)
This International Standard specifies the procedure to be used for determining the CIE whiteness of papers and boards, in order to obtain values which correspond to the visual appearance of white papers and boards, with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is limited to the blue region of VIS. This International Standard also specifies the procedures for the determination of CIE tint values and the fluorescent component of CIE whiteness.
In addition, it specifies a method for adjustment of the UV content to correspond to that of CIE illuminant C [10][11], since the results obtained when fluorescent whitening agents are present are dependent upon the UV content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of indoor illumination conditions because it contains a suitable proportion of UV radiation [12][13]. This method is not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the fluorescence occurs in the blue region of the visible spectral range.
This International Standard is read in conjunction with ISO 2469.
NOTE 1 It is recognized that the CIE whiteness equation was developed in the context of the CIE standard illuminant D65 [6], but the similarity between the relative spectral power curves for the C and D65 illuminants within the visible region and the closeness of their correlated colour temperatures (6 770 K and 6 500 K respectively) are taken as a justification for the use of the analogous whiteness equation with the CIE illuminant C.
NOTE 2 A related International Standard, ISO 11475 [4] specifies the procedure for obtaining values corresponding to the appearance of papers viewed under the CIE standard illuminant D65.
Papier et carton -- Détermination du degré de blanc CIE C/2 degrés (éclairage intérieur)
L'ISO 11476:2010 sp�cifie le mode op�ratoire � utiliser pour d�terminer le degr� de blanc CIE des papiers et cartons afin d'obtenir des valeurs correspondant � l'aspect visuel des papiers et cartons blancs, avec ou sans agents d'azurage fluorescents, lorsqu'ils sont observ�s � l'int�rieur. Elle est fond�e sur des valeurs de facteur de luminance �nerg�tique obtenues pour toute l'�tendue du spectre visible, contrairement au mesurage du degr� de blancheur ISO qui est limit� � la r�gion bleue du spectre visible. L'ISO 11476:2010 sp�cifie �galement les modes op�ratoires permettant de d�terminer les valeurs de teinte CIE et la composante de fluorescence du degr� de blanc CIE.
En outre, elle sp�cifie une m�thode permettant de r�gler la teneur en UV afin qu'elle corresponde � celle de l'illuminant CIE C, puisque les valeurs obtenues lorsque des agents d'azurage fluorescents sont pr�sents d�pendent de la teneur en UV du rayonnement arrivant sur l'�chantillon. L'illuminant CIE C est consid�r� comme �tant repr�sentatif des conditions d'�clairage int�rieur puisqu'il contient une quantit� ad�quate de rayonnement UV. Cette m�thode ne convient pas aux papiers de couleur contenant des colorants fluorescents. Elle est sp�cifique au cas o� la fluorescence intervient dans la r�gion bleue de l'�tendue du spectre visible.
L'ISO 11476:2010 s'utilise conjointement avec l'ISO 2469.
Papir, karton in lepenka - Določanje beline po CIE, C/2° (pogoji osvetlitve v prostoru)
Ta mednarodni standard opredeljuje postopek, ki se uporablja za določanje beline papirjev, kartonov in lepenk po CIE, z namenom pridobiti vrednosti, ki ustrezajo videzu vrst belega papirja, kartona, lepenka, s fluorescenčnimi belilnimi sredstvi ali brez njih, pri ogledu v prostoru. Temelji na podatkih o faktorju odsevnosti, pridobljenih čez celotno vidno območje spektra (VIS), v nasprotju z merjenjem beline po ISO, ki je omejena na modro področje VIS. Ta mednarodni standard tudi opredeljuje postopke za določanje vrednosti odtenka CIE in fluorescenčne komponente beline po CIE.
Poleg tega opredeljuje metodo za prilagoditev vsebnosti UV, da ustreza vrsti svetlobe CIE C [10][11], ker so rezultati, pridobljeni v prisotnosti fluorescenčnih belilnih sredstev, odvisni od vsebnosti UV sevanja, ki pada na vzorec. Vrsta svetlobe CIE C je vzeta kot reprezentativna za pogoje osvetlitve v prostoru, ker vsebuje primeren delež sevanja UV [12][13]. Ta metoda se ne uporablja za obarvane papirje, ki vsebujejo fluorescenčna barvila. Velja posebej za situacije, kjer se fluorescenca pojavi v modrem področju vidnega območja spektra.
Ta mednarodni standard se bere skupaj z ISO 2469.
OPOMBA 1: Znano je, da je bila enačba beline po CIE razvita v kontekstu standardne vrste svetlobe CIE D65 [6], a podobnost med krivuljami moči relativnega spektra za vrste svetlobe C in D65 v vidnem območju, in bližina njihovih povezanih barvnih temperatur (6 770 K in 6 500 K v tem vrstnem redu) se upoštevajo kot utemeljitev za uporabo analogne enačbe beline z vrsto svetlobe CIE C.
OPOMBA 2: Povezan mednarodni standard ISO 11475 [4] opredeljuje postopek za pridobivanje vrednosti, ki ustrezajo videzu papirjev pod standardno vrsto svetlobe CIE D65.
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INTERNATIONAL ISO
STANDARD 11476
Second edition
2010-08-01
Paper and board — Determination of CIE
whiteness, C/2° (indoor illumination
conditions)
Papier et carton — Détermination du degré de blanc CIE C/2°
(éclairage intérieur)
Reference number
ISO 11476:2010(E)
©
ISO 2010
---------------------- Page: 1 ----------------------
ISO 11476:2010(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 2010
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 copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2010 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 11476:2010(E)
Contents Page
Foreword .iv
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Principle.3
5 Apparatus and equipment .3
6 Calibration.4
7 Sampling and conditioning .5
8 Preparation of test pieces.5
9 Procedure.5
10 Calculation and expression of results .5
11 Precision.6
12 Test report.7
Annex A (normative) Spectral characteristics of reflectometers for determining tristimulus values .8
Annex B (normative) UV calibration service.11
Bibliography.13
© ISO 2010 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 11476:2010(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 11476 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps. It is based on the CIE
whiteness formula, published in CIE 15:2004, Colorimetry.
This second edition cancels and replaces the first edition (ISO 11476:2000), which has been technically
revised to include the option to condition samples before measurements.
iv © ISO 2010 – All rights reserved
---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 11476:2010(E)
Paper and board — Determination of CIE whiteness, C/2°
(indoor illumination conditions)
1 Scope
This International Standard specifies the procedure to be used for determining the CIE whiteness of papers
and boards, in order to obtain values which correspond to the visual appearance of white papers and boards,
with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data
obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is
limited to the blue region of VIS. This International Standard also specifies the procedures for the
determination of CIE tint values and the fluorescent component of CIE whiteness.
In addition, it specifies a method for adjustment of the UV content to correspond to that of CIE illuminant
[10][11]
C , since the results obtained when fluorescent whitening agents are present are dependent upon the
UV content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of
[12][13]
indoor illumination conditions because it contains a suitable proportion of UV radiation . This method is
not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the
fluorescence occurs in the blue region of the visible spectral range.
This International Standard is read in conjunction with ISO 2469.
NOTE 1 It is recognized that the CIE whiteness equation was developed in the context of the CIE standard illuminant
[6]
D65 , but the similarity between the relative spectral power curves for the C and D65 illuminants within the visible region
and the closeness of their correlated colour temperatures (6 770 K and 6 500 K respectively) are taken as a justification
for the use of the analogous whiteness equation with the CIE illuminant C.
[4]
NOTE 2 A related International Standard, ISO 11475 specifies the procedure for obtaining values corresponding to
the appearance of papers viewed under the CIE standard illuminant D65.
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, 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)
© ISO 2010 – All rights reserved 1
---------------------- Page: 5 ----------------------
ISO 11476:2010(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
reflectance factor
R
ratio of the radiation reflected by a body to that reflected by the perfect reflecting diffuser under the same
conditions
NOTE The reflectance factor is usually expressed as a percentage.
3.2
intrinsic reflectance factor
reflectivity
R
∞
reflectance factor of a layer or pad of the material thick enough to be opaque, i.e. such that increasing the
thickness of the pad by doubling the number of sheets results in no change in the measured reflectance factor
3.3
radiance factor
β
ratio of the radiance of a body to that of the perfect reflecting diffuser under the same conditions of illumination
and viewing
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
ββ=+β
SL
For non-fluorescent materials, the reflected radiance factor, β , is simply the reflectance factor, R.
S
3.4
intrinsic radiance factor
β
∞
radiance factor of a layer or pad of the material thick enough to be opaque, i.e. such that increasing the
thickness of the pad by doubling the number of sheets results in no change in the measured radiance factor
NOTE For fluorescent (luminescent) materials, the intrinsic total radiance factor, β , is the sum of two portions, the
∞
intrinsic reflected radiance factor, β , and the intrinsic luminescent radiance factor, β , so that
∞,S ∞,L
ββ=+β
∞∞,S ∞,L
For non-fluorescent materials, the intrinsic reflected radiance factor, β , is simply the intrinsic reflectance factor, R .
∞,S ∞
3.5
CIE whiteness
W
measure of CIE whiteness derived from the CIE tristimulus values determined under the conditions specified
in this International Standard
NOTE The CIE whiteness is expressed in CIE whiteness units.
3.6
green/red tint
T
w
measure of the deviation from CIE whiteness of the test material towards the green or red region
NOTE 1 The deviation is expressed as CIE tint units.
NOTE 2 A positive value of T indicates a greenish tint and a negative value indicates a reddish tint.
w
2 © ISO 2010 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 11476:2010(E)
3.7
fluorescence component
W
F
measure of the extent to which the CIE whiteness of the material is affected by excitation of the added
fluorescent whitening agent (FWA) under the conditions specified in this International Standard
4 Principle
The diffuse radiance factor of the material is determined under standardized conditions after adjustment of the
instrument so that the relative UV content of the illumination corresponds to that of the CIE illuminant C, and
the CIE whiteness and tint are calculated. The fluorescence component of the CIE whiteness is calculated
from the difference between the diffuse radiance factor value and the value obtained when the fluorescence
emission from the material is eliminated, for instance by the introduction into the light beams of a sharp-cut-off
UV-absorbing filter.
5 Apparatus and equipment
5.1 Reflectometer or spectrophotometer, having the geometric, spectral and photometric characteristics
described in ISO 2469, calibrated in accordance with the provisions of ISO 2470-1, and equipped with a
radiation source having an adequate UV content and a means of adjusting the relative UV content so that the
measured ISO brightness value agrees with the ISO brightness value assigned to a fluorescent reference
standard (5.2.2) and corresponding to the CIE illuminant C (References [7], [8] and [11] in the Bibliography). If
a filter (the UV-adjustment filter) is used to make this adjustment, it shall have a cut-off value of 395 nm so
that it absorbs UV radiation but does not, at the same time, alter the visible spectrum within the sphere.
NOTE In order to achieve concordance between the conditions for measuring both ISO brightness and CIE
whiteness (C/2°), an adjustment based on a fluorescent reference standard (5.2.2) having an assigned ISO brightness
value is preferred.
For the measurement of reflectance factors with the fluorescence effect eliminated, the instrument shall be
equipped with a sharp-cut-off, UV-absorbing filter (the UV cut-off filter) having a transmittance not exceeding
5,0 % at and below a wavelength of 410 nm and not exceeding 50 % at a wavelength of 420 nm. The cut-off
filter shall have characteristics such that a repeatable reflectance factor value is obtained at 420 nm. The
reflectance factor value obtained at 420 nm shall then be considered for computational purposes to be the
value which applies at all lower wavelengths, at which it is not possible to make any measurement.
For the measurement of fluorescent papers, photometric linearity up to a scale reading of at least 200 % is
necessary in the wavelength region corresponding to the fluorescent emission.
5.1.1 In the case of a filter reflectometer, pairs of filters giving the photoelectric detectors of the
reflectometer responses equivalent to the CIE tristimulus values X, Y, Z of the test piece (Reference [7] in the
Bibliography), evaluated for the CIE illuminant C (Reference [8] in the Bibliography) and CIE 1931 (2°)
observer (Reference [5] in the Bibliography).
5.1.2 In the case of an abridged spectrophotometer, a means of calculating the weighted means in
accordance with the requirements of the CIE illuminant C and CIE 1931 (2°) observer using the weighting
functions given in Annex A.
5.2 Reference standards for calibration of the instrument and working standards
5.2.1 Non-fluorescent reference standard for calibration, fulfilling the requirements for ISO reference
standards of level 3, as specified in ISO 2470-1.
5.2.2 Fluorescent reference standard for use in adjusting the UV content of the radiation incident upon the
sample, having an assigned ISO brightness value, as specified in Annex B, and fulfilling the requirements for
ISO reference standards of level 3, as specified in ISO 2470-1.
Use new reference standards sufficiently frequently to ensure satisfactory calibration and UV adjustment.
© ISO 2010 – All rights reserved 3
---------------------- Page: 7 ----------------------
ISO 11476:2010(E)
5.3 Working standards
5.3.1 Two plates of flat opal glass or ceramic material, cleaned as described in ISO 2469.
5.3.2 A stable plastic or other tablet incorporating a fluorescent whitening agent.
5.4 Black cavity, having a reflectance factor which does not differ from its nominal value by more than
0,2 % at all wavelengths. The black cavity should be stored upside down in a dust-free environment or with a
protective cover.
The condition of the black cavity should be checked by reference to the instrument maker.
6 Calibration
6.1 Using the values assigned to the non-fluorescent reference standard (5.2.1), calibrate the instrument
with the UV cut-off filters removed from the radiation beams. The setting of the UV-adjustment filter is not
important at this stage.
6.2 Using the appropriate measurement procedure, measure the reflectance of the fluorescent reference
standard (5.2.2), determine the ISO brightness value as specified in ISO 2470-1 and compare the value
obtained with that assigned to the fluorescent reference standard.
A measured ISO brightness value higher than the assigned value indicates that the relative UV content of the
illumination is too high and a lower value indicates that the relative UV content is too low.
6.3 Using the UV-adjustment filter or other adjustment device, adjust the UV content of the illumination until
measurement gives the correct ISO brightness value.
6.4 Repeat the calibration as described in 6.1 using the non-fluorescent standard (5.2.1) with the UV
adjustment in the position which gave the correct ISO brightness value for the fluorescent reference standard.
Repeat the measurement of the brightness of the fluorescent standard (5.2.2) as described in 6.2. If the ISO
brightness value obtained does not agree with the assigned value, adjust the position of the UV adjustment
filter or other adjustment device until the measurement gives the correct ISO brightness value as described in
6.3.
6.5 Repeat the procedure described in 6.4 until the correct value for the ISO brightness of the fluorescent
standard (5.2.2) is obtained with the instrument correctly calibrated to the non-fluorescent standard (5.2.1).
The UV content is now correctly adjusted with respect to brightness to a relative UV content equivalent to the
CIE illuminant C. Record the setting of the UV adjustment.
NOTE 1 This setting means that the illumination in the instrument corresponds to the CIE illuminant C for ISO
brightness measurement and it will give acceptable agreement for CIE whiteness (C/2°). Variations in the green/red tint
value might still arise and it cannot be assumed that the tristimul
...
SLOVENSKI STANDARD
SIST ISO 11476:2011
01-maj-2011
3DSLUNDUWRQLQOHSHQND'RORþDQMHEHOLQHSR&,(&ƒ SRJRMLRVYHWOLWYHY
SURVWRUX
Paper and board -- Determination of CIE whiteness, C/2 degrees (indoor illumination
conditions)
Papier et carton -- Détermination du degré de blanc CIE C/2 degrés (éclairage intérieur)
Ta slovenski standard je istoveten z: ISO 11476:2010
ICS:
85.060 Papir, karton in lepenka Paper and board
SIST ISO 11476:2011 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST ISO 11476:2011
---------------------- Page: 2 ----------------------
SIST ISO 11476:2011
INTERNATIONAL ISO
STANDARD 11476
Second edition
2010-08-01
Paper and board — Determination of CIE
whiteness, C/2° (indoor illumination
conditions)
Papier et carton — Détermination du degré de blanc CIE C/2°
(éclairage intérieur)
Reference number
ISO 11476:2010(E)
©
ISO 2010
---------------------- Page: 3 ----------------------
SIST ISO 11476:2011
ISO 11476:2010(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 2010
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 copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2010 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 11476:2011
ISO 11476:2010(E)
Contents Page
Foreword .iv
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Principle.3
5 Apparatus and equipment .3
6 Calibration.4
7 Sampling and conditioning .5
8 Preparation of test pieces.5
9 Procedure.5
10 Calculation and expression of results .5
11 Precision.6
12 Test report.7
Annex A (normative) Spectral characteristics of reflectometers for determining tristimulus values .8
Annex B (normative) UV calibration service.11
Bibliography.13
© ISO 2010 – All rights reserved iii
---------------------- Page: 5 ----------------------
SIST ISO 11476:2011
ISO 11476:2010(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 11476 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps. It is based on the CIE
whiteness formula, published in CIE 15:2004, Colorimetry.
This second edition cancels and replaces the first edition (ISO 11476:2000), which has been technically
revised to include the option to condition samples before measurements.
iv © ISO 2010 – All rights reserved
---------------------- Page: 6 ----------------------
SIST ISO 11476:2011
INTERNATIONAL STANDARD ISO 11476:2010(E)
Paper and board — Determination of CIE whiteness, C/2°
(indoor illumination conditions)
1 Scope
This International Standard specifies the procedure to be used for determining the CIE whiteness of papers
and boards, in order to obtain values which correspond to the visual appearance of white papers and boards,
with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data
obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is
limited to the blue region of VIS. This International Standard also specifies the procedures for the
determination of CIE tint values and the fluorescent component of CIE whiteness.
In addition, it specifies a method for adjustment of the UV content to correspond to that of CIE illuminant
[10][11]
C , since the results obtained when fluorescent whitening agents are present are dependent upon the
UV content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of
[12][13]
indoor illumination conditions because it contains a suitable proportion of UV radiation . This method is
not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the
fluorescence occurs in the blue region of the visible spectral range.
This International Standard is read in conjunction with ISO 2469.
NOTE 1 It is recognized that the CIE whiteness equation was developed in the context of the CIE standard illuminant
[6]
D65 , but the similarity between the relative spectral power curves for the C and D65 illuminants within the visible region
and the closeness of their correlated colour temperatures (6 770 K and 6 500 K respectively) are taken as a justification
for the use of the analogous whiteness equation with the CIE illuminant C.
[4]
NOTE 2 A related International Standard, ISO 11475 specifies the procedure for obtaining values corresponding to
the appearance of papers viewed under the CIE standard illuminant D65.
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, 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)
© ISO 2010 – All rights reserved 1
---------------------- Page: 7 ----------------------
SIST ISO 11476:2011
ISO 11476:2010(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
reflectance factor
R
ratio of the radiation reflected by a body to that reflected by the perfect reflecting diffuser under the same
conditions
NOTE The reflectance factor is usually expressed as a percentage.
3.2
intrinsic reflectance factor
reflectivity
R
∞
reflectance factor of a layer or pad of the material thick enough to be opaque, i.e. such that increasing the
thickness of the pad by doubling the number of sheets results in no change in the measured reflectance factor
3.3
radiance factor
β
ratio of the radiance of a body to that of the perfect reflecting diffuser under the same conditions of illumination
and viewing
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
ββ=+β
SL
For non-fluorescent materials, the reflected radiance factor, β , is simply the reflectance factor, R.
S
3.4
intrinsic radiance factor
β
∞
radiance factor of a layer or pad of the material thick enough to be opaque, i.e. such that increasing the
thickness of the pad by doubling the number of sheets results in no change in the measured radiance factor
NOTE For fluorescent (luminescent) materials, the intrinsic total radiance factor, β , is the sum of two portions, the
∞
intrinsic reflected radiance factor, β , and the intrinsic luminescent radiance factor, β , so that
∞,S ∞,L
ββ=+β
∞∞,S ∞,L
For non-fluorescent materials, the intrinsic reflected radiance factor, β , is simply the intrinsic reflectance factor, R .
∞,S ∞
3.5
CIE whiteness
W
measure of CIE whiteness derived from the CIE tristimulus values determined under the conditions specified
in this International Standard
NOTE The CIE whiteness is expressed in CIE whiteness units.
3.6
green/red tint
T
w
measure of the deviation from CIE whiteness of the test material towards the green or red region
NOTE 1 The deviation is expressed as CIE tint units.
NOTE 2 A positive value of T indicates a greenish tint and a negative value indicates a reddish tint.
w
2 © ISO 2010 – All rights reserved
---------------------- Page: 8 ----------------------
SIST ISO 11476:2011
ISO 11476:2010(E)
3.7
fluorescence component
W
F
measure of the extent to which the CIE whiteness of the material is affected by excitation of the added
fluorescent whitening agent (FWA) under the conditions specified in this International Standard
4 Principle
The diffuse radiance factor of the material is determined under standardized conditions after adjustment of the
instrument so that the relative UV content of the illumination corresponds to that of the CIE illuminant C, and
the CIE whiteness and tint are calculated. The fluorescence component of the CIE whiteness is calculated
from the difference between the diffuse radiance factor value and the value obtained when the fluorescence
emission from the material is eliminated, for instance by the introduction into the light beams of a sharp-cut-off
UV-absorbing filter.
5 Apparatus and equipment
5.1 Reflectometer or spectrophotometer, having the geometric, spectral and photometric characteristics
described in ISO 2469, calibrated in accordance with the provisions of ISO 2470-1, and equipped with a
radiation source having an adequate UV content and a means of adjusting the relative UV content so that the
measured ISO brightness value agrees with the ISO brightness value assigned to a fluorescent reference
standard (5.2.2) and corresponding to the CIE illuminant C (References [7], [8] and [11] in the Bibliography). If
a filter (the UV-adjustment filter) is used to make this adjustment, it shall have a cut-off value of 395 nm so
that it absorbs UV radiation but does not, at the same time, alter the visible spectrum within the sphere.
NOTE In order to achieve concordance between the conditions for measuring both ISO brightness and CIE
whiteness (C/2°), an adjustment based on a fluorescent reference standard (5.2.2) having an assigned ISO brightness
value is preferred.
For the measurement of reflectance factors with the fluorescence effect eliminated, the instrument shall be
equipped with a sharp-cut-off, UV-absorbing filter (the UV cut-off filter) having a transmittance not exceeding
5,0 % at and below a wavelength of 410 nm and not exceeding 50 % at a wavelength of 420 nm. The cut-off
filter shall have characteristics such that a repeatable reflectance factor value is obtained at 420 nm. The
reflectance factor value obtained at 420 nm shall then be considered for computational purposes to be the
value which applies at all lower wavelengths, at which it is not possible to make any measurement.
For the measurement of fluorescent papers, photometric linearity up to a scale reading of at least 200 % is
necessary in the wavelength region corresponding to the fluorescent emission.
5.1.1 In the case of a filter reflectometer, pairs of filters giving the photoelectric detectors of the
reflectometer responses equivalent to the CIE tristimulus values X, Y, Z of the test piece (Reference [7] in the
Bibliography), evaluated for the CIE illuminant C (Reference [8] in the Bibliography) and CIE 1931 (2°)
observer (Reference [5] in the Bibliography).
5.1.2 In the case of an abridged spectrophotometer, a means of calculating the weighted means in
accordance with the requirements of the CIE illuminant C and CIE 1931 (2°) observer using the weighting
functions given in Annex A.
5.2 Reference standards for calibration of the instrument and working standards
5.2.1 Non-fluorescent reference standard for calibration, fulfilling the requirements for ISO reference
standards of level 3, as specified in ISO 2470-1.
5.2.2 Fluorescent reference standard for use in adjusting the UV content of the radiation incident upon the
sample, having an assigned ISO brightness value, as specified in Annex B, and fulfilling the requirements for
ISO reference standards of level 3, as specified in ISO 2470-1.
Use new reference standards sufficiently frequently to ensure satisfactory calibration and UV adjustment.
© ISO 2010 – All rights reserved 3
---------------------- Page: 9 ----------------------
SIST ISO 11476:2011
ISO 11476:2010(E)
5.3 Working standards
5.3.1 Two plates of flat opal glass or ceramic material, cleaned as described in ISO 2469.
5.3.2 A stable plastic or other tablet incorporating a fluorescent whitening agent.
5.4 Black cavity, having a reflectance factor which does not differ from its nominal value by more than
0,2 % at all wavelengths. The black cavity should be stored upside down in a dust-free environment or with a
protective cover.
The condition of the black cavity should be checked by reference to the instrument maker.
6 Calibration
6.1 Using the values assigned to the non-fluorescent reference standard (5.2.1), calibrate the instrument
with the UV cut-off filters removed from the radiation beams. The setting of the UV-adjustment filter is not
important at this stage.
6.2 Using the appropriate measurement procedure, measure the reflectance of the fluorescent reference
standard (5.2.2), determine the ISO brightness value as specified in ISO 2470-1 and compare the value
obtained with that assigned to the fluorescent reference standard.
A measured ISO brightness value higher than the assigned value indicates that the relative UV content of the
illumination is too high and a lower value indicates that the relative UV content is too low.
6.3 Using the UV-adjustment filter or other adjustment device, adjust the UV content of the illumination until
measurement gives the correct ISO brightness value.
6.4 Repeat the calibration as described in 6.1 using the non-fluorescent standard (5.2.1) with the UV
adjustment in the position which gave the correct ISO brightness value for the fluorescent reference standard.
Repeat the measurement of the brightness of the fluorescent standard (5.2.2) as described in 6.2. If the ISO
brightness value obtained does not agree with the assigned value, adjust the position of the UV adjustment
filter or other adjustment device until the measurement gives the correct ISO brightness value as described in
6.3.
6.5 Repeat the procedure described in 6.4 until the correct value for the ISO brightness of the fluorescent
standard (5.2.2) is obtained with the instrument correctly calibrated to the non-fluorescent standard (5.2.1).
The UV content is now correctly adjusted with respect to
...
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.SURVWRUXPapier et carton -- Détermination du degré de blanc CIE C/2 degrés (éclairage intérieur)Paper and board -- Determination of CIE whiteness, C/2 degrees (indoor illumination conditions)85.060Papir, karton in lepenkaPaper and boardICS:Ta slovenski standard je istoveten z:ISO 11476:2010oSIST ISO 11476:2011en01-marec-2011oSIST ISO 11476:2011SLOVENSKI
STANDARD
oSIST ISO 11476:2011
Reference numberISO 11476:2010(E)© ISO 2010
INTERNATIONAL STANDARD ISO11476Second edition2010-08-01Paper and board — Determination of CIE whiteness, C/2° (indoor illumination conditions) Papier et carton — Détermination du degré de blanc CIE C/2° (éclairage intérieur)
oSIST ISO 11476:2011
ISO 11476:2010(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.
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ii
© ISO 2010 – All rights reserved
oSIST ISO 11476:2011
ISO 11476:2010(E) © ISO 2010 – All rights reserved
iii Contents Page Foreword.iv 1 Scope.1 2 Normative references.1 3 Terms and definitions.2 4 Principle.3 5 Apparatus and equipment.3 6 Calibration.4 7 Sampling and conditioning.5 8 Preparation of test pieces.5 9 Procedure.5 10 Calculation and expression of results.5 11 Precision.6 12 Test report.7 Annex A (normative)
Spectral characteristics of reflectometers for determining tristimulus values.8 Annex B (normative)
UV calibration service.11 Bibliography.13
oSIST ISO 11476:2011
ISO 11476:2010(E) iv
© ISO 2010 – 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 11476 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps. It is based on the CIE whiteness formula, published in CIE 15:2004, Colorimetry. This second edition cancels and replaces the first edition (ISO 11476:2000), which has been technically revised to include the option to condition samples before measurements.
oSIST ISO 11476:2011
INTERNATIONAL STANDARD ISO 11476:2010(E) © ISO 2010 – All rights reserved
1 Paper and board — Determination of CIE whiteness, C/2° (indoor illumination conditions) 1 Scope This International Standard specifies the procedure to be used for determining the CIE whiteness of papers and boards, in order to obtain values which correspond to the visual appearance of white papers and boards, with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is limited to the blue region of VIS. This International Standard also specifies the procedures for the determination of CIE tint values and the fluorescent component of CIE whiteness. In addition, it specifies a method for adjustment of the UV content to correspond to that of CIE illuminant C [10][11], since the results obtained when fluorescent whitening agents are present are dependent upon the UV content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of indoor illumination conditions because it contains a suitable proportion of UV radiation [12][13]. This method is not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the fluorescence occurs in the blue region of the visible spectral range. This International Standard is read in conjunction with ISO 2469. NOTE 1 It is recognized that the CIE whiteness equation was developed in the context of the CIE standard illuminant D65 [6], but the similarity between the relative spectral power curves for the C and D65 illuminants within the visible region and the closeness of their correlated colour temperatures (6 770 K and 6 500 K respectively) are taken as a justification for the use of the analogous whiteness equation with the CIE illuminant C. NOTE 2 A related International Standard, ISO 11475 [4] specifies the procedure for obtaining values corresponding to the appearance of papers viewed under the CIE standard illuminant D65. 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, 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) oSIST ISO 11476:2011
ISO 11476:2010(E) 2
© ISO 2010 – All rights reserved 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 reflectance factor R ratio of the radiation reflected by a body to that reflected by the perfect reflecting diffuser under the same conditions NOTE The reflectance factor is usually expressed as a percentage. 3.2 intrinsic reflectance factor reflectivity R∞ reflectance factor of a layer or pad of the material thick enough to be opaque, i.e. such that increasing the thickness of the pad by doubling the number of sheets results in no change in the measured reflectance factor 3.3 radiance factor β ratio of the radiance of a body to that of the perfect reflecting diffuser under the same conditions of illumination and viewing NOTE For fluorescent (luminescent) materials, the total radiance factor, β, is the sum of two portions, the reflected radiance factor, β S, and the luminescent radiance factor, β L, so that SLβββ=+ For non-fluorescent materials, the reflected radiance factor, β S, is simply the reflectance factor, R. 3.4 intrinsic radiance factor β∞ radiance factor of a layer or pad of the material thick enough to be opaque, i.e. such that increasing the thickness of the pad by doubling the number of sheets results in no change in the measured radiance factor NOTE For fluorescent (luminescent) materials, the intrinsic total radiance factor, β ∞, is the sum of two portions, the intrinsic reflected radiance factor, β ∞,S, and the intrinsic luminescent radiance factor, β ∞,L, so that ,S,Lβββ∞∞∞=+ For non-fluorescent materials, the intrinsic reflected radiance factor, β ∞,S, is simply the intrinsic reflectance factor, R ∞. 3.5 CIE whiteness W measure of CIE whiteness derived from the CIE tristimulus values determined under the conditions specified in this International Standard NOTE The CIE whiteness is expressed in CIE whiteness units. 3.6 green/red tint Tw measure of the deviation from CIE whiteness of the test material towards the green or red region NOTE 1 The deviation is expressed as CIE tint units. NOTE 2 A positive value of Tw indicates a greenish tint and a negative value indicates a reddish tint. oSIST ISO 11476:2011
ISO 11476:2010(E) © ISO 2010 – All rights reserved
3 3.7 fluorescence component WF measure of the extent to which the CIE whiteness of the material is affected by excitation of the added fluorescent whitening agent (FWA) under the conditions specified in this International Standard 4 Principle The diffuse radiance factor of the material is determined under standardized conditions after adjustment of the instrument so that the relative UV content of the illumination corresponds to that of the CIE illuminant C, and the CIE whiteness and tint are calculated. The fluorescence component of the CIE whiteness is calculated from the difference between the diffuse radiance factor value and the value obtained when the fluorescence emission from the material is eliminated, for instance by the introduction into the light beams of a sharp-cut-off UV-absorbing filter. 5 Apparatus and equipment 5.1 Reflectometer or spectrophotometer, having the geometric, spectral and photometric characteristics described in ISO 2469, calibrated in accordance with the provisions of ISO 2470-1, and equipped with a radiation source having an adequate UV content and a means of adjusting the relative UV content so that the measured ISO brightness value agrees with the ISO brightness value assigned to a fluorescent reference standard (5.2.2) and corresponding to the CIE illuminant C (References [7], [8] and [11] in the Bibliography). If a filter (the UV-adjustment filter) is used to make this adjustment, it shall have a cut-off value of 395 nm so that it absorbs UV radiation but does not, at the same time, alter the visible spectrum within the sphere. NOTE In order to achieve concordance between the conditions for measuring both ISO brightness and CIE whiteness (C/2°), an adjustment based on a fluorescent reference standard (5.2.2) having an assigned ISO brightness value is preferred. For the measurement of reflectance factors with the fluorescence effect eliminated, the instrument shall be equipped with a sharp-cut-off, UV-absorbing filter (the UV cut-off filter) having a transmittance not exceeding 5,0 % at and below a wavelength of 410 nm and not exceeding 50 % at a wavelength of 420 nm. The cut-off filter shall have characteristics such that a repeatable reflectance factor value is obtained at 420 nm. The reflectance factor value obtained at 420 nm shall then be considered for computational purposes to be the value which applies at all lower wavelengths, at which it is not possible to make any measurement. For the measurement of fluorescent papers, photometric linearity up to a scale reading of at least 200 % is necessary in the wavelength region corresponding to the fluorescent emission. 5.1.1 In the case of a filter reflectometer, pairs of filters giving the photoelectric detectors of the reflectometer responses equivalent to the CIE tristimulus values X, Y, Z of the test piece (Reference [7] in the Bibliography), evaluated for the CIE illuminant C (Reference [8] in the Bibliography) and CIE 1931 (2°) observer (Reference [5] in the Bibliography). 5.1.2 In the case of an abridged spectrophotometer, a means of calculating the weighted means in accordance with the requirements of the CIE illuminant C and CIE 1931 (2°) observer using the weighting functions given in Annex A. 5.2 Reference standards for calibration of the instrument and working standards 5.2.1 Non-fluorescent reference standard for calibration, fulfilling the requirements for ISO reference standards of level 3, as specified in ISO 2470-1. 5.2.2 Fluorescent reference standard for use in adjusting the UV content of the radiation incident upon the sample, having an assigned ISO brightness value, as specified in Annex B, and fulfilling the requirements for ISO reference standards of level 3, as specified in ISO 2470-1. Use new reference standards sufficiently frequently to ensure satisfactory calibration and UV adjustment. oSIST ISO 11476:2011
ISO 11476:2010(E) 4
© ISO 2010 – All rights reserved 5.3 Working standards 5.3.1 Two plates of flat opal glass or ceramic material, cleaned as described in ISO 2469. 5.3.2 A stable plastic or other tablet incorporating a fluorescent whitening agent. 5.4 Black cavity, having a reflectance factor which does not differ from its nominal value by more than 0,2 % at all wavelengths. The black cavity should be stored upside down in a dust-free environment or with a protective cover. The condition of the black cavity should be checked by reference to the instrument maker. 6 Calibration 6.1 Using the values assigned to the non-fluorescent reference standard (5.2.1), calibrate the instrument with the UV cut-off filters removed from the radiation beams. The setting of the UV-adjustment filter is not important at this stage. 6.2 Using the appropriate measurement procedure, measure the reflectance of the fluorescent reference standard (5.2.2), determine the ISO brightness value as specified in ISO 2470-1 and compare the value obtained with that assigned to the fluorescent reference standard. A measured ISO brightness value higher than the assigned value indicates that the relative UV content of the illumination is too high and a lower value indicates that the relative UV content is too low. 6.3 Using the UV-adjustment filter or other adjustment device, adjust the UV content of the illumination until measurement gives the correct ISO brightness value. 6.4 Repeat the calibration as described in 6.1 using the non-fluorescent standard (5.2.1) with the UV adjustment in the position which gave the correct ISO brightness value for the fluorescent reference standard. Repeat the measurement of the brightness of the fluorescent standard (5.2.2) as described in 6.2. If the ISO brightness value obtained does not agree with the assigned value, adjust the position of the UV adjustment filter or other adjustment device until the measurement gives the correct ISO brightness value as described in 6.3. 6.5 Repeat the procedure described in 6.4 until the correct value for the ISO brightness of the fluorescent standard (5.2.2) is obtained with the instrument correctly calibrated to the non-fluorescent stand
...
NORME ISO
INTERNATIONALE 11476
Deuxième édition
2010-08-01
Papier et carton — Détermination du
degré de blanc CIE C/2° (éclairage
intérieur)
Paper and board — Determination of CIE whiteness, C/2° (indoor
illumination conditions)
Numéro de référence
ISO 11476:2010(F)
©
ISO 2010
---------------------- Page: 1 ----------------------
ISO 11476:2010(F)
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Publié en Suisse
ii © ISO 2010 – Tous droits réservés
---------------------- Page: 2 ----------------------
ISO 11476:2010(F)
Sommaire Page
Avant-propos .iv
1 Domaine d'application .1
2 Références normatives.1
3 Termes et définitions .2
4 Principe.3
5 Appareillage et équipement .3
6 Étalonnage .4
7 Échantillonnage et conditionnement .5
8 Préparation des éprouvettes.5
9 Mode opératoire.5
10 Calcul et expression des résultats .6
11 Fidélité .7
12 Rapport d'essai.7
Annexe A (normative) Caractéristiques spectrales des réflectomètres pour la détermination des
composantes trichromatiques .8
Annexe B (normative) Service d'étalonnage UV.11
Bibliographie.13
© ISO 2010 – Tous droits réservés iii
---------------------- Page: 3 ----------------------
ISO 11476:2010(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 11476 a été élaborée par le comité technique ISO/TC 6, Papiers, cartons et pâtes. Elle est fondée sur
la formule du degré de blanc CIE, donnée dans la CIE 15:2004, Colorimétrie.
Cette deuxième édition annule et remplace la première édition (ISO 11476:2000), qui a fait l'objet d'une
révision technique pour inclure l'option de conditionnement des échantillons avant les mesurages.
iv © ISO 2010 – Tous droits réservés
---------------------- Page: 4 ----------------------
NORME INTERNATIONALE ISO 11476:2010(F)
Papier et carton — Détermination du degré de blanc CIE C/2°
(éclairage intérieur)
1 Domaine d'application
La présente Norme internationale spécifie le mode opératoire à utiliser pour déterminer le degré de blanc CIE
des papiers et cartons afin d'obtenir des valeurs correspondant à l'aspect visuel des papiers et cartons blancs,
avec ou sans agents d'azurage fluorescents, lorsqu'ils sont observés à l'intérieur. Elle est fondée sur des
valeurs de facteur de luminance énergétique obtenues pour toute l'étendue du spectre visible, contrairement
au mesurage du degré de blancheur ISO qui est limité à la région bleue du spectre visible. La présente Norme
internationale spécifie également les modes opératoires permettant de déterminer les valeurs de teinte CIE et
la composante de fluorescence du degré de blanc CIE.
En outre, elle spécifie une méthode permettant de régler la teneur en UV afin qu'elle corresponde à celle de
[10][11]
l'illuminant CIE C , puisque les valeurs obtenues lorsque des agents d'azurage fluorescents sont
présents dépendent de la teneur en UV du rayonnement arrivant sur l'échantillon. L'illuminant CIE C est
considéré comme étant représentatif des conditions d'éclairage intérieur puisqu'il contient une quantité
[12][13]
adéquate de rayonnement UV . Cette méthode ne convient pas aux papiers de couleur contenant des
colorants fluorescents. Elle est spécifique au cas où la fluorescence intervient dans la région bleue de
l'étendue du spectre visible.
La présente Norme internationale s'utilise conjointement avec l'ISO 2469.
NOTE 1 Il est reconnu que l'équation du degré de blanc CIE a été développée dans le contexte de l'illuminant
[6]
normalisé CIE D65 , mais la similarité entre les courbes de puissance spectrale relative pour les illuminants C et D65
dans le visible et la proximité des températures de couleur correspondantes (6 770 K et 6 500 K respectivement) sont
considérées comme justifiant l'utilisation de l'équation analogue de degré de blanc avec l'illuminant CIE C.
[4]
NOTE 2 Une Norme internationale apparentée, l'ISO 11475 , spécifie le mode opératoire pour obtenir les valeurs
correspondant à l'aspect de papiers observés sous l'illuminant normalisé CIE D65.
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, 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)
© ISO 2010 – Tous droits réservés 1
---------------------- Page: 5 ----------------------
ISO 11476:2010(F)
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s'appliquent.
3.1
facteur de réflectance
R
rapport du rayonnement réfléchi par un corps au rayonnement réfléchi dans les mêmes conditions par le
diffuseur parfait par réflexion
NOTE Le facteur de réflectance est exprimé habituellement en pourcentage.
3.2
facteur de réflectance intrinsèque
R
∞
facteur de réflectance 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 réflectance mesuré
3.3
facteur de luminance énergétique
β
rapport de la luminance énergétique d'un corps à celle du diffuseur parfait par réflexion, dans les mêmes
conditions d'éclairage et d'observation
NOTE Pour les matériaux fluorescents (luminescents), le facteur de luminance énergétique totale, 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 :
L
β = β + β
S L
Pour les matériaux non fluorescents, le facteur de luminance énergétique par réflexion, β , est simplement le facteur de
S
réflectance, R.
3.4
facteur de luminance énergétique intrinsèque
β
∞
facteur de luminance 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 énergétique mesuré
NOTE Pour les matériaux fluorescents (luminescents), le facteur de luminance énergétique intrinsèque totale, β , est
∞
la somme de deux grandeurs, le facteur de luminance énergétique intrinsèque par réflexion, β , et le facteur de
∞,S
luminance énergétique intrinsèque par luminescence, β :
∞,L
β = b + b
∞ ∞,S ∞,L
Pour les matériaux non fluorescents, le facteur de luminance énergétique intrinsèque par réflexion, β , est simplement le
∞,S
facteur de réflectance intrinsèque, R .
∞
3.5
degré de blanc CIE
W
mesure du degré de blanc CIE, dérivée des composantes trichromatiques CIE déterminées dans les
conditions spécifiées dans la présente Norme internationale
NOTE Le degré de blanc CIE est exprimé en unités de degré de blanc CIE.
2 © ISO 2010 – Tous droits réservés
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ISO 11476:2010(F)
3.6
teinte vert/rouge
T
w
mesure de la déviation du degré de blanc CIE du matériau soumis à essai vers la région du vert ou du rouge
NOTE 1 La déviation est exprimée en unités de teinte CIE.
NOTE 2 Une valeur positive de T indique une teinte tirant sur le vert, et une valeur négative une teinte tirant sur le
w
rouge.
3.7
composante de fluorescence
W
F
mesure de l'importance de la modification du degré de blanc CIE du matériau par l'excitation des agents
d'azurage fluorescents ajoutés, dans les conditions spécifiées dans la présente Norme internationale
4 Principe
Le facteur de luminance énergétique diffuse du matériau est déterminé dans des conditions normalisées
après réglage de l'appareil, de sorte que la teneur relative en UV de l'éclairage corresponde à celle de
l'illuminant CIE C, et le degré de blanc CIE et la teinte sont calculés. La composante de fluorescence du
degré de blanc CIE est calculée comme étant la différence entre la valeur du facteur de luminance
énergétique diffuse et la valeur obtenue après élimination de l'émission fluorescente du matériau, par
exemple en insérant dans les faisceaux lumineux un filtre absorbant les UV, à coupure nette.
5 Appareillage et équipement
5.1 Réflectomètre ou spectrophotomètre, ayant les caractéristiques géométriques, spectrales et
photométriques décrites dans l'ISO 2469, étalonné conformément aux dispositions de l'ISO 2470-1, et équipé
d'une source de rayonnement à teneur adéquate en UV et d'un moyen de réglage de la teneur relative en UV,
de sorte que la valeur mesurée du degré de blancheur ISO concorde avec la valeur de degré de blancheur
ISO assignée à un étalon de référence fluorescent (5.2.2), et correspondant à l'illuminant CIE C
(Références [7], [8] et [11]). Si un filtre (le filtre de réglage de teneur en UV) est utilisé pour faire ce réglage, il
doit avoir une coupure nette à 395 nm afin d'absorber tout rayonnement UV sans altérer le spectre visible à
l'intérieur de la sphère.
NOTE Afin d'obtenir une concordance entre les conditions pour mesurer à la fois le degré de blancheur ISO et le
degré de blanc CIE (C/2°), un ajustement fondé sur un étalon de référence fluorescent (5.2.2) qui a une valeur assignée
de degré de blancheur ISO est préféré.
Pour le mesurage des facteurs de réflectance après élimination de la fluorescence, l'appareil doit être équipé
d'un filtre absorbant les UV, de coupure nette, dont le facteur de transmission n'excède pas 5,0 % à une
longueur d'onde inférieure ou égale à 410 nm, et pas plus de 50 % à une longueur d'onde de 420 nm. Le filtre
à coupure doit avoir des caractéristiques telles qu'une valeur reproductible du facteur de réflectance soit
obtenue à 420 nm. La valeur du facteur de réflectance obtenue à 420 nm doit alors être considérée pour les
calculs comme la valeur applicable à toutes les longueurs d'onde inférieures, pour lesquelles il est impossible
de faire un mesurage.
Pour le mesurage des papiers fluorescents, il est nécessaire d'avoir une linéarité photométrique, au moins
jusqu'à la graduation 200 %, dans la région des longueurs d'onde correspondant à l'émission fluorescente.
5.1.1 Pour les réflectomètres à filtres, des paires de filtres donnant aux cellules photoélectriques des
réflectomètres des réponses équivalentes aux composantes trichromatiques CIE X, Y, Z de l'éprouvette
(Référence [7]), évaluées pour l'illuminant normalisé CIE C (Référence [8]) et l'observateur CIE 1931 (2°)
(Référence [5]).
5.1.2 Pour les spectrophotomètres avec un nombre discret de longueurs d'onde, un moyen permettant de
calculer les moyennes pondérées conformément aux exigences relatives à l'illuminant CIE C et à
l'observateur CIE 1931 (2°) en utilisant les fonctions de pondération données dans l'Annexe A.
© ISO 2010 – Tous droits réservés 3
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ISO 11476:2010(F)
5.2 Étalons de référence pour l'étalonnage de l'appareil et des étalons de travail
5.2.1 Étalon de référence non fluorescent pour l'étalonnage, conforme aux exigences relatives aux étalons
de référence ISO de niveau 3, comme spécifié dans l'ISO 2470-1.
5.2.2 Étalon de référence fluorescent destiné au réglage de la teneur en UV du rayonnement incident sur
l'échantillon, ayant une valeur assignée de degré de blancheur ISO comme spécifié dans l'Annexe B et
conforme aux exigences relatives aux étalons de référence ISO de niveau 3, comme spécifié dans
l'ISO 2470-1.
Renouveler les étalons de référence suffisamment souvent afin d'assurer un étalonnage et un réglage de la
teneur en UV satisfaisants.
5.3 Étalons de travail
5.3.1 Deux plaques planes de verre opale ou céramique, nettoyées comme décrit dans l'ISO 2469.
5.3.2 Tablette de plastique stable ou d'un autre matériau stable contenant un agent d'azurage fluorescent.
5.4 Corps noir, dont le facteur de réflectance ne varie pas de plus de 0,2 % par rapport à la valeur
nominale, à toutes les longueurs d'onde. Il convient d'entreposer le corps noir, côté supérieur en dessous,
dans un environnement exempt de poussière, ou sous un couvercle protecteur.
Il convient que l'état du corps noir soit contrôlé en s'adressant au fabricant de l'appareil.
6 Étalonnage
6.1 En utilisant les valeurs assignées à l'étalon de référence non fluorescent (5.2.1), étalonner l'appareil
après avoir retiré des faisceaux lumineux les filtres anti-UV. La position du filtre de réglage de la teneur en UV
n'est pas importante à ce stade.
6.2 En utilisant le mode opératoire de mesurage approprié, mesurer la réflectance de l'étalon de référence
fluorescent (5.2.2), déterminer sa valeur de degré de blancheur ISO comme spécifié dans I'ISO 2470-1 et
comparer la valeur obtenue avec celle assignée à l'étalon de référence fluorescent.
Une valeur de degré de blancheur ISO mesurée plus élevée que la valeur assignée signifie que la teneur
relative en UV de l'éclairage est trop élevée, tandis qu'une valeur mesurée inférieure à la valeur assignée
signifie que la teneur relative en UV est trop basse.
6.3 En utilisant le filtre de réglage de la teneur en UV ou un autre dispositif de réglage, régler la teneur en
UV de l'éclairage de façon à obtenir la valeur correcte de degré de blancheur ISO.
6.4 Répéter l'étalonnage décrit en 6.1 en utilisant l'étalon non fluorescent (5.2.1), avec le filtre de réglage
de la teneur en UV dans la position pour laquelle la valeur correcte de degré de blancheur ISO a été obtenue
pour l'étalon de référence fluorescent. Répéter le mesurage du degré de blancheur de l'étalon
fluorescent (5.2.2) comme décrit en 6.2. Si la valeur du degré de blancheur ISO obtenue ne concorde pas
avec la valeur assignée, régler la position du filtre de réglage de la teneur en UV ou d'un autre dispositif de
réglage jusqu'à obtention de la valeur correcte du degré de blancheur ISO comme décrit en 6.3.
6.5 Répéter le mode opératoire décrit en 6.4 jusqu'à obtention de la valeur correcte de degré de blancheur
ISO de l'étalon fluorescent (5.2.2) avec l'appareil étalonné correctement avec l'étalon non fluorescent (5.2.1).
La teneur en UV est maintenant réglée correctement par rapport au degré de blancheur, à une teneur relative
en UV équivalente à l'illuminant CIE C. Noter la position de réglage de la teneur en UV.
NOTE 1 Cette position signifie que l'éclairage dans l'appareil correspond à l'illuminant CIE C pour le mesurage du
degré de blancheur ISO, et elle donnera un niveau de concordance acceptable pour le degré de blanc CIE (C/2°). Il peut y
avoir encore des variations dans les teintes vert/rouge et il n'est pas possible de présumer que les composantes
trichromatiques et d'autres paramètres seront aussi exactement ceux applicables à l'illuminant C.
NOTE 2 Pour certains appareils, le mode opératoire indiqué de 6.2 à 6.5 s'ef
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