1、BSI Standards PublicationBS ISO 17221:2014Plastics Determinationof image clarity (degree ofsharpness of reflected ortransmitted image)BS ISO 17221:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 17221:2014.The UK participation in its preparation was entrus
2、ted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British
3、 Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 79262 5ICS 83.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 May 2014.A
4、mendments issued since publicationDate Text affectedBS ISO 17221:2014 ISO 2014Plastics Determination of image clarity (degree of sharpness of reflected or transmitted image)Plastiques Dtermination de la clart de limage (degr de nettet de limage rflchie ou transmise)INTERNATIONAL STANDARDISO17221Firs
5、t edition2014-05-01Reference numberISO 17221:2014(E)BS ISO 17221:2014ISO 17221:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means,
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7、. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 17221:2014ISO 17221:2014(E) ISO 2014 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Instrument 16 Te
8、st specimen 47 Procedure. 47.1 Zero adjustment . 47.2 Sensitivity adjustment 57.3 Measurement on the test specimen 58 Calculation 59 Test report . 6Annex A (informative) Example of determination . 7Annex B (informative) Precision 10Bibliography .12BS ISO 17221:2014ISO 17221:2014(E)ForewordISO (the I
9、nternational 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
10、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 electrotechnica
11、l standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in a
12、ccordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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. Det
13、ails of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an e
14、ndorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee re
15、sponsible for this document is ISO/TC 61, Plastics, Subcommittee SC 5, Physical chemical properties.iv ISO 2014 All rights reservedBS ISO 17221:2014ISO 17221:2014(E)IntroductionVisual assessment of the image clarity of plastics is carried out by evaluating the sharpness of an image reflected from a
16、surface, using a specified incident angle, for reflection. For transmission, image sharpness is evaluated by viewing a suitable target through the plastic. The degree of image clarity is influenced by the clearness, surface irregularities and haziness of surfaces. Gloss meters and haze meters do not
17、 correctly access this phenomenon. Image clarity is not the same as and should not be confused with gloss or haze. Therefore, standardized methods for determining the optical parameter of image clarity are needed. ISO 2014 All rights reserved vBS ISO 17221:2014BS ISO 17221:2014Plastics Determination
18、 of image clarity (degree of sharpness of reflected or transmitted image)1 ScopeThis International Standard specifies an instrumental method for determining the image clarity on plastics specimens by measuring reflection from the specimen surface or transmission through the specimen.The method can b
19、e applied only to a flat surface.NOTE For same materials, different values of image clarity can be obtained depending on specimen preparation.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For
20、 dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 472, Plastics VocabularyISO 2813, Paints and varnishes Determination of specular gloss of non-metallic paint films at 20, 60 and 85ISO 11664
21、-1, Colorimetry Part 1: CIE standard colorimetric observersISO 11664-2, Colorimetry Part 2: CIE standard illuminants3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 472 and the following apply.3.1image claritydegree of sharpness of an image reflected b
22、y a specimen or transmitted through a specimenNote 1 to entry: Image clarity is expressed in percentage (%).4 PrincipleFor the measurement of image clarity, a lamp illuminates the narrow source aperture-slit. The collimating lens projects a parallel beam upon the specimen. The image is either reflec
23、ted from or transmitted through the specimen, as appropriate. The image is received by the de-collimating lens and focused upon the optical mask. The light passing through the optical mask is received by the light receptor. This resultant signal is processed yielding image clarity values.5 Instrumen
24、t5.1 Light source and spectral response. The light source and the photometer shall be used in conjunction with a filter to provide an output corresponding to the photopic standard luminous efficiency V(), which is identical to the colour-matching function y() specified in ISO 11664-1, under CIE stan
25、dard illuminant A as specified in ISO 11664-2. The output of the photodetector shall be proportional to the INTERNATIONAL STANDARD ISO 17221:2014(E) ISO 2014 All rights reserved 1BS ISO 17221:2014ISO 17221:2014(E)incident flux, to within 1 % of the incident flux, over the range used. The spectral an
26、d photometric characteristics of the light source and photometer shall be kept constant during measurements.5.2 Slit, 0,03 mm 0,01 mm in width and not less than 20 mm in length.5.3 Optical mask, consisting of opaque and transparent lines having the same width and spacing. Six different groups of lin
27、es having different widths are utilized. An optical mask is illustrated in Figure 1. Table 1 gives the dimension for the lines of the optical mask.Keya opaque area Group 1 transparent and opaque lines each 2,0 mm in widthb transparent area Group 2 transparent and opaque lines each 1,0 mm in widthc w
28、idth of opaque area Group 3 transparent and opaque lines each 0,5 mm in widthd width of transparent area Group 4 transparent and opaque lines each 0,25 mm in widthGroup 5 transparent and opaque lines each 0,125 mm in widthGroup 6 opaque line 1,0 mm in widthFigure 1 Optical mask of image clarityTable
29、 1 Optical mask (dimensions)Group No.Optical mask line width mmQuantityTolerance mmGroup width mm1 2,000 4 0,200 162 1,000 6 0,100 123 0,500 9 0,050 94 0,250 16 0,025 85 0,125 21 0,013 5,2561,000 (only opaque)1 0,100 1NOTE Other dimensions of the optical mask may be used depending on the surface str
30、ucture of the specimen if agreed upon between the interested parties.2 ISO 2014 All rights reservedBS ISO 17221:2014ISO 17221:2014(E)5.4 Geometry (for reflection measurement). The normal geometry is 45:45. The 60:60 may be used if agreed upon between the interested parties.NOTE The 60:60 geometry ma
31、y be used depending on the surface structure of the specimen for conforming the visual assessments.5.5 Black glass standard, giving a constant light intensity when any of the five line widths of optical mask is used for passing light. The bottom level of the waves is defined as the standard zero lev
32、el.The black glass standard surface used should conform to specifications such as given in ISO 2813.5.6 Structure. A diagrammatic representation of the apparatus used for evaluation of image clarity in transmission is shown in Figure 2. Figure 3 shows a diagrammatic representation for reflection mea
33、surement of image clarity.Key1 light source 5 de-collimating lens with a focal length 130 mm2 source aperture-slit 6 optical mask3 collimating lens with a focal length 130 mm 7 image of source aperture-slit on the optical mask4 specimen 8 light receptorFigure 2 Typical diagrammatic representation fo
34、r transmission measurement of image clarity ISO 2014 All rights reserved 3BS ISO 17221:2014ISO 17221:2014(E)Key1 light source 5 de-collimating lens with a focal length 130 mm2 source aperture-slit 6 optical mask3 collimating lens with a focal length 130 mm 7 image of source aperture-slit on the opti
35、cal mask4 specimen 8 light receptora 45 or 60Figure 3 Typical diagrammatic representation for reflection measurement of image clarity6 Test specimenFor transmission and reflection, the size of the test specimen should be:a) not less than 30 mm 30 mm,b) not larger than 150 mm 150 mm, andc) less than
36、10 mm in thickness.7 Procedure7.1 Zero adjustmentMake a zero adjustment using the dark portion of the optical mask without specimen for transmission and with the black glass standard for reflection.4 ISO 2014 All rights reservedBS ISO 17221:2014ISO 17221:2014(E)7.2 Sensitivity adjustmentScan the opt
37、ical mask over its full range and adjust the full scale standardization sensitivity so that the maximum signal is not saturating the electronics. That is increasing the sensitivity and causes a corresponding change in signal at maximum signal condition.7.3 Measurement on the test specimenSome specim
38、ens exhibit directionality. For those specimens, it is necessary to measure in one orientation, rotate 90 and measure again. If necessary, carry out measurements for other additional orientations. Record the image clarity values and the orientation of the specimen relative to the slit.If specimens e
39、xhibit directionality and image clarity values do not conform to visual assessment, it is necessary to measure another direction.8 CalculationCalculate the image clarity value from the wave heights using Formula (1) (see Figure 4);CnMmMmnnnn() (%)=+100 (1)whereC(n) is the image clarity value, expres
40、sed as a percentage, at n (mm) of the optical mask line width;Mnis the maximum relative light intensity at n (mm) of the optical mask line width;mnis the minimum relative light intensity at n (mm) of the optical mask line width.NOTE 1 When the image clarity value is high, the image can be seen clear
41、ly. On the contrary, when the image clarity value is low, the image is distorted.NOTE 2 Examples of determination of image clarity are shown in Annex A.NOTE 3 Precision of the image clarity is shown in Annex B. ISO 2014 All rights reserved 5BS ISO 17221:2014ISO 17221:2014(E)KeyX groupY relative ligh
42、t intensityMnmaximum relative light intensity at n (mm) of optical mask line widthmnminimum relative light intensity at n (mm) of optical mask line widthFigure 4 Example of the received relative light intensity of a specimen9 Test reportThe test report shall contain at least the following informatio
43、n:a) a reference to this International Standard, i.e. ISO 17221;b) a description of the specimen measured, including material and shape;c) the method of measurement (transmission/reflection);d) in case of measurement by reflection, the measurement angle;e) if each side has different surface conditio
44、n, the side used for the measurement;f) if the specimen has the orientation of the specimen relative to the slit, the direction of measurement;g) the image clarity value(s) and optical mask line width(s);h) the date of the measurement.6 ISO 2014 All rights reservedBS ISO 17221:2014ISO 17221:2014(E)A
45、nnex A (informative) Example of determinationA.1 Selection of optical mask widthIt is desirable to select optical mask line width depending on conformity to the visual assessment. There are five optical masks which differ in the line widths of the opaque and transparent areas.For high image clarity
46、specimens, use 0,125 mm and 0,25 mm in line width.For medium image clarity specimens, use 0,50 mm in line width.For low image clarity (matt) specimens, use 1,0 mm and 2,0 mm in line width.These five widths are sufficient to assess image clarity. Image clarity values of five optical mask line widths
47、are measured at the same time. The optical mask line width is selected to conform to visual assessments referred to in Tables A.1 to A.4.A.2 Example of image clarity measurement (transmission)Table A.1 shows haze values and image clarity values for four kinds of plastic films.Table A.1 Measurement o
48、f plastic films (transmission)Specimen no.Specimen characteris-tics (thickness, mm)Haze value (%)C(n) Image clarity value (%)Visual assess-mentC (0,125)C (0,25)C (0,5)C (1,0)C (2,0)11Film (0,06 mm)1,57 91,5 92,0 93,0 92,9 97,1 Clear12Film (0,2 mm)14,11 74,8 75,4 80,0 82,0 90,4 Slightly hazy13Film (0
49、,1 mm)33,18 67,8 68,6 75,3 77,2 88,5 Hazy14Anti-glare film (0,08 mm)14,67 6,3 5,7 5,9 11,6 38,4Considerably hazySpecimens 1-1 to 1-3 are plastic films with different haze values. Specimen 1-4 is an anti-glare film. When this film is placed just above a paper, the characters can be seen. On the contrary, when the film is moved away from the paper, the characters cannot be seen.Haze values of specimens 1-1 to 1-3 conform to visual assessment as image clarity values do.Comparing specimen
