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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 5631:2000 ICS 85.0
2、60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Paper and board Determination of colour (C/2) Diffuse reflectance method Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared un
3、der the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 March 2001 BSI 03-2001 ISBN 0 580 36954 4 BS ISO 5631:2000 Amendments issued since publication Amd. No.DateComments National foreword This B
4、ritish Standard reproduces verbatim ISO 5631:2000 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee PAI/11, Methods of test for paper, board and pulp, which has the responsibility to: aid enquirers to understand the text; pres
5、ent to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can b
6、e obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, or by using the Find facility of
7、 the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.
8、Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na,
9、Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO 5631:2000(E) INTERNATIONAL STANDARD ISO 5631 First edition 2000-03-01 Paper and board Determination of colour (C/2) Diffuse reflectance method Papier et carton Dtermination de la couleur (C/2) Mthode par rflectance d
10、iffuse Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) ii? Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) iii ContentsPage Foreword.iv Introduction
11、.v 1Scope 1 2Normative references1 3Terms and definitions .1 4Principle2 5Apparatus.2 6Sampling.3 7Preparation of test pieces.3 8Procedure.3 9Calculation3 10Expression of results 4 11Test report5 Annex A (normative) Calculation of tristimulus values 6 Bibliography9 Licensed Copy: sheffieldun sheffie
12、ldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) iv 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
13、 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
14、 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 3. Draft International Standards adopted by the technical committe
15、es 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 International Standard may be the subject of patent rights. ISO
16、shall not be held responsible for identifying any or all such patent rights. International Standard ISO 5631 was prepared by Technical Committee ISO/TC 6,Paper, board and pulps. Annex A forms a normative part of this International Standard. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:2
17、2:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) v Introduction The colour of an object can be uniquely characterized by means of a triplet of colour coordinates such as the 1931 CIE tristimulus values, the CIELAB 1976 L*, a*, b* coordinates or the dominant wavelength, excitation pur
18、ity and luminous reflectance. The values of such coordinates depend upon the conditions of measurement, particularly the spectral and geometric characteristics of the instrument used. This International Standard should therefore be read in conjunction with ISO 2469. This method describes the measure
19、ment and description of colour in terms of the CIE illuminant C and the CIE 1931 (2) standard observer. The measurement and calculations can be carried out in an analogous manner with respect to the CIE standard illuminant D65 and the CIE 1964 (10) standard observer or with other illuminant/observer
20、 combinations, but this is not in accordance with this International Standard. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNA
21、TIONAL STANDARDISO 5631:2000(E) 1 Paper and board Determination of colour (C/2) Diffuse reflectance method 1Scope This International Standard specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. This International St
22、andard 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 th
23、at in the CIE illuminant C using a fluorescent reference standard provided by an authorized laboratory as described in ISO 2470. 2Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For
24、 dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For
25、 undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 186:1994,Paper and board Sampling to determine average quality. ISO 2469,Paper, board and pulps Measurement of diffuse refl
26、ectance factor. CIE Publication 15.2:1986,Colorimetry. ASTM E 308-95,Standard Practice for Computing the Colors of Objects by Using the CIE System. 3Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. 3.1 reflectance factor R ratio of the
27、 radiation reflected by a body to that reflected by the perfect reflecting diffuser under the same conditions of illumination and detection NOTE 1The reflectance factor is expressed as a percentage. NOTE 2The reflectance factor is influenced by the backing if the body is translucent. Licensed Copy:
28、sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) 2 3.2 intrinsic reflectance factor R? reflectance factor of a layer or pad of material thick enough to be opaque, i.e. such that increasing the thickness of the pad by doubling the number of
29、sheets leads to no change in the measured reflectance factor 3.3 tristimulus values X, Y, Z amounts of the three reference colour stimuli, in a given trichromatic system, required to match the stimulus considered NOTEIn this International Standard, the CIE 1931 standard observer and the CIE illumina
30、nt C are used to define the trichromatic system. 3.4 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 4Principle The light reflected from a sample under specifi
31、ed conditions is analysed either by a tristimulus-filter colorimeter or by an abridged spectrophotometer, and the colour coordinates are then calculated. 5Apparatus 5.1Reflectometer, having the geometric, spectral and photometric characteristics described in ISO 2469 and calibrated in accordance wit
32、h the provisions of ISO 2469. NOTEIn the 1994 edition of ISO 2469 the reflectometer characteristics are described in annex A and the calibration service is described in annex B. When ISO 2469 is revised, the numbering may change; users of editions subsequent to 1994 should therefore determine which
33、elements of text specify these characteristics and this service. 5.2Filter-function 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
34、 CIE 1931 standard colorimetric system of the test piece evaluated for the CIE illuminant C. In the case of an abridged spectrophotometer, a function that permits calculation of the CIE tristimulus values X, Y and Z of the CIE 1931 standard colorimetric system of the test piece evaluated for the CIE
35、 illuminant C using the weighting functions given in annex A. 5.3Reference standards, issued by an ISO/TC 6 authorized laboratory in accordance with the provisions of ISO 2469 for calibration of the instrument and the working standards. For maximum accuracy, reference standards having assigned value
36、s within the maximum range expected for the particular product to be tested should be selected. If there is reason to suspect that the instrument has poor linearity or that the deviations from the true colour matching and observer functions are greater than can be tolerated, the use of product-speci
37、fic reference standards should be considered. 5.4Working standards, calibrated in the instrument concerned against ISO reference standards of level 3 supplied by an authorized laboratory (see ISO 2469). Calibrate the working standards sufficiently frequently to ensure that satisfactory calibration i
38、s maintained. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) 3 Use newly calibrated reference standards sufficiently frequently to ensure that the reflectometer is maintained in agreement with the reference instrument. 5.5B
39、lack 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. NOTE 1The condition of the black cavity can be checked by reference to th
40、e instrument maker. NOTE 2The nominal value is given by the manufacturer. 6Sampling If the tests are being made to evaluate a lot, the sample shall be selected in accordance with ISO 186. If the tests are made on another type of sample, make sure that the test pieces taken are representative of the
41、sample received. 7Preparation of test pieces Avoiding watermarks, dirt and obvious defects, cut rectangular test pieces approximately 75 mm ? 150 mm. Assemble at least ten test pieces in a pad with their top sides uppermost; the number should be such that doubling the number of test pieces does not
42、alter the reflectance factor. Protect the pad by placing an additional sheet of paper or board on both the top and bottom of the pad; avoid contamination and unnecessary exposure to light or heat. Mark the top test piece in one corner to identify the sample and its top side, or to distinguish betwee
43、n the two sides. If the top side can be distinguished from the wire side, it shall be uppermost; if not, as may be the case for papers manufactured on twin-wire machines, ensure that the same side of the sheet is uppermost. 8Procedure Remove the protecting sheets from the top and bottom of the test
44、piece pad. Without touching the test area, use the working standard and the procedure appropriate to the instrument to obtain the three CIE tristimulus values of the first test piece (or CIELAB values if the instrument is designed to report directly in this colour space). Read and record the values
45、to the nearest 0,05 unit. Move the uppermost test piece to the bottom of the pad and determine the values for succeeding test pieces until at least ten test pieces have been evaluated. If required, repeat the procedure for the other side of the test pieces. 9Calculation 9.1CIE tristimulus values If
46、the instrument has a bandpass of 5 nm or narrower, calculate the CIE tristimulus values in accordance with CIE Publication 15.2:1986. In all other cases, calculate the tristimulus values using the appropriate weighting functions given in ASTM E 308-95. If the instrument does not provide the CIE tris
47、timulus values directly, obtain them by calculation using the tables provided in annex A. 9.2CIELAB coordinates Calculate the CIELAB coordinates from the tristimulus values X,Y,Z by means of the following equations: LY Yn* / ?11616 1 3 bg(1) Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 08:
48、22:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5631:2000(E) 4 aX XY Y nn * / ?500 1 31 3 bgbg(2) bY YZ Z nn * / ?200 1 31 3 bgbg(3) where Xn, Yn, Znare the tristimulus values of the perfect reflecting diffuser under C/2 conditions. These are given as the “White point“ values in annex A. Correc
49、tions shall be introduced for very dark samples. If Y/Ynu 0,008 856, replace the expression for L* by ?*903,3 n LY Y?(4) and if any of the ratios X/Xn, Y/Yn, Z/Znu0,008 856, replace it in the equations for a* and b* by the expression: 778716,F ?116(5) where F is X/Xn, Y/Ynor Z/Zn,as the case may be. 9.3Dispersion of the results Since the three-dimensional statistical calculations are extremely complicated, the following simple procedure for assessing the dispersion is recommended: Calculate the mean values of , and . Calculate for each test piece