1、BRITISH STANDARD BS EN ISO 3668:2001 BS 3900-D1: 1998 Incorporating Amendment No. 1 to BS 3900-D1:1998 (renumbers the BS as BS EN ISO 3668:2001) Paints and varnishes Visual comparison of the colour of paints The European Standard EN ISO 3668:2001 has the status of a British Standard ICS 87.040 NO CO
2、PYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN ISO 3668:2001 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 October 1998 BSI
3、1 October 2001 ISBN 0 580 30619 4 National foreword This British Standard is the official English language version of EN ISO 3668:2001. It is identical with ISO 3668:1998. The UK participation in its preparation was entrusted to Technical Committee STI/10, Methods of test for paints, which has the r
4、esponsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interest informed; monitor related international and European developments and promulgate them in the UK.
5、The main differences between BS 3900-D1:1978 and this Part of BS 3900 are as follows: a) the standard is technically updated; b) a colour difference rating scheme is included. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The Brit
6、ish Standards which implement international or European 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 the BSI Standards Electronic Catalogue. A Britis
7、h 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. Summary of pages This document comprises a front
8、cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, page ii, pages 1 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. N
9、o. Date Comments 13287 01 October 2001 Implementation of the European StandardEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 3668 May 2001 ICS 87.040 English version P a i n t s a n d v a r n i s h e s V i s u a l c o m p a r i s o n o f t h e c o l o u r of paints (ISO 3668:1998) Peinture
10、s et vernis Comparaison visuelle de la couleur des peintures (ISO 3668:1998) Beschichtungsstoffe Visueller Vergleich der Farbe von Beschichtungen (Farbabmusterung) (ISO 3668:1988) This European Standard was approved by CEN on 7 March 2001. CEN members are bound to comply with the CEN/CENELEC Interna
11、l Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member Thi
12、s European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the
13、national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation E
14、uropisches Komitee fr Normung Management Centre: Rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref. No. EN ISO 3668:2001 EEN ISO 3668:2001 BSI 01 October 2001 Foreword The text of the International Sta
15、ndard from Technical Committee ISO/TC 35, Paints and varnishes, of the International Organization for Standardization (ISO) has been taken over as a European Standard by Technical Committee CEN/TC 139, Paints and varnishes, the Secretariat of which is held by DIN. This European Standard shall be giv
16、en the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2001, and conflicting national standards shall be withdrawn at the latest by November 2001. According to the CEN/CENELEC Internal Regulations, the national standards organiza
17、tions of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.EN ISO 3668:2001 ii BSI 0
18、1 October 2001 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 subjec
19、t 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)
20、 on all matters of electrotechnical standardization. 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. International Standa
21、rd ISO 3668 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9, General test methods for paints and varnishes. This second edition cancels and replaces the first edition (ISO 3668:1976), which has been technically revised. Annex A and Annex B form an integral part
22、 of this International Standard. Annex C is for information only. Descriptors: Paints, varnishes, tests, daylight tests, artificial light tests, determination, colour, visual inspection (testing), comparison analysis, standard colour.EN ISO 3668:2001 BSI 01 October 2001 1 1 Scope This International
23、Standard is one of a series of standards dealing with the sampling and testing of paints, varnishes and related products. It specifies a method for the visual comparison of the colour of films of paints or related products against a standard (either a reference standard or a freshly prepared standar
24、d) using either natural daylight or artificial light sources in a standard booth. It is not applicable to coatings containing special-effect pigments, e.g. metallics, without previous agreement on all details of illuminating and viewing conditions. 2 Normative references The following standards cont
25、ain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investiga
26、te the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1512:1991, Paints and varnishes Sampling of products in liquid or paste form. ISO 1513:1992, Paints and varnishes Examin
27、ation and preparation of samples for testing. ISO 1514:1993, Paints and varnishes Standard panels for testing. ISO 2808:1997, Paints and varnishes Determination of film thickness. ISO 3270:1984, Paints and varnishes and their raw materials Temperatures and humidities for conditioning and testing. IS
28、O 7724-1:, Paints and varnishes Colorimetry Part 1: Principles 1) . ISO 7724-2:, Paints and varnishes Colorimetry Part 2: Colour measurement 2) . ISO 7724-3:, Paints and varnishes Colorimetry Part 3: Calculation of colour differences by CIELAB 3) . CIE Publication No. 51:1981, A method for assessing
29、 the quality of daylight simulators for colorimetry. CIE Publication No. 15.2:1986, Colorimetry. 3 Principle The colours of the paint films to be compared are observed under specified illumination and viewing conditions, either in natural daylight or in artificial light, using a colour-matching boot
30、h in the latter case. For the expression of colour difference components (hue, chroma and lightness), a procedure is described, i.e. description using a particular rating scheme. Assessment of metamerism is also taken into account. 4 Required supplementary information For any particular application,
31、 the test method specified in this International Standard needs to be completed by supplementary information. The items of supplementary information are given in Annex A. 5 Illumination for colour matching 5.1 General For routine colour matching, either natural or artificial daylight may be used. Th
32、e quality of natural daylight is variable, and observers judgements are likely to be affected by nearby coloured objects. For reference purposes therefore, closely controlled artificial illumination in a colour-matching booth shall be used. The observer shall wear clothing of a neutral colour, and n
33、o strongly coloured surfaces, other than the panels under test, shall be permitted in the field of view. 1) To be published. (Revision of ISO 7724-1:1984) 2) To be published. (Revision of ISO 7724-2:1984) 3) To be published. (Revision of ISO 7724-3:1984)EN ISO 3668:2001 2 BSI 01 October 2001 5.2 Nat
34、ural daylight illumination Diffuse daylight, preferably from a partially cloudy north sky in the northern hemisphere and a partially cloudy south sky in the southern hemisphere, and not reflected from any strongly coloured object such as a red brick wall or green tree, shall be used. Illumination sh
35、all be uniform over the area in which test panels are displayed and at a level of at least 2 000 lx. Direct sunlight shall be avoided. 5.3 Artificial illumination by means of a colour-matching booth The colour-matching booth shall be an enclosure from which external light is excluded and which is il
36、luminated by a light source giving a spectral power distribution falling on the test panel, approximating to that of CIE standard illuminant D65 or CIE standard illuminant A. Where a light source having a different spectral distribution is used, it shall be agreed by the interested parties. The qual
37、ity of simulation of daylight shall be assessed by the method described in CIE Publication No. 51. The spectral distribution of the illuminant shall be in category BC (CIELAB) or better. The level of illumination at the colour-matching position shall be between 1 000 lx and 4 000 lx, a figure toward
38、s the upper end of the range being desirable for dark colours. The interior of the colour-matching booth for general use shall be painted a matt neutral grey (the amount of a *and b *shall be less than 1,0) with a lightness L *of about 45 to 55. However, when mainly light colours and near-white colo
39、urs are to be compared, the interior of the booth may be painted so as to have a lightness L *of about 65 or higher in order to give a lower brightness contrast with the colour to be examined; when mainly dark colours are to be compared, the interior of the booth may be painted matt black with a lig
40、htness L *of about 25. NOTE L * , a *and b *refer to the CIELAB system (see ISO 7724-1). To ensure an appropriate surrounding field for colour comparison, the table surface in the booth shall be covered by a neutral grey panel, its luminance factor being chosen to be similar to that of the samples t
41、o be compared. A diffusing screen shall normally be used to avoid the reflection of an image of the lamp from the test panel. The spectral distribution properties of the light source shall include the spectral transmission of the screen. The manufacturer of the light source shall disclose the number
42、 of running hours during which the product can be expected to conform to this International Standard. 6 Observer Observers shall have normal colour vision and shall be selected carefully because a significant proportion of people have defective colour vision. An lshihara test will reveal severe defe
43、cts but, to confirm an observers suitability, more sensitive tests, for example the Farnsworth 100 hue test or stricter anomaloscope measurements, are desirable. If an observer wears glasses to correct his or her vision, these shall have uniform spectral transmission throughout the visible spectrum.
44、 As colour vision changes significantly with age, it is desirable that observers over 40 years of age are tested using a proper method whereby the observer is requested to choose the best match from a metameric series of colours. For colour comparison work, not only normal colour vision but also col
45、our discrimination ability or experience is important. To avoid eye fatigue effects, pastel or complementary colours shall not be viewed immediately after strong colours. When comparing bright, saturated colours, if a decision cannot be made rapidly, the observer shall look away for some seconds at
46、the neutral grey of the surrounding field before attempting a further comparison. The quality of visual judgements falls off severely if the observer works continuously. Rest periods of several minutes during which no colour matching is attempted shall, therefore, be taken frequently.EN ISO 3668:200
47、1 BSI 01 October 2001 3 7 Test panels and reference standards 7.1 General Both test panels and reference colour standards shall be flat and preferably about 150 mm 100 mm in size. Suitable materials for test panels are tinplate, hard aluminium, glazed cardboard, steel or glass, complying with ISO 15
48、14. Panel size and viewing distance shall be chosen so that the panel subtends an angle at the eye of about 10 . If larger panels are used, a viewing field corresponding to the 10 observer shall be formed using a grey mask. Typical viewing distances and sizes for the square openings in the mask are
49、given in Table 1. Table 1 Viewing distances and opening sizes of masks 7.2 Reference standards Only colour standards of satisfactory colour permanence shall be used as reference standards. Wherever possible, the reference standards shall be of the same size as the test panels and shall have closely similar gloss and surface texture. 7.3 Preparation and coating Prepare test panels as specified and, where appropriate, in accordance with ISO 1514. The panels shall be coated by a closely specified or agreed method, be
