1、BSI Standards PublicationBS ISO 8254-3:2016Paper and board Measurement of specular glossPart 3: 20ogloss with a converging beam, TAPPI methodBS ISO 8254-3:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 8254-3:2016. It supersedes BS ISO 8254-3:2004 which i
2、s withdrawn. The UK participation in its preparation was entrusted to Technical Committee PAI/11, Methods of test for paper, board and pulps.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessar
3、y provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 86891 7 ICS 85.060 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was pu
4、blished under the authority of the Standards Policy and Strategy Committee on 30 April 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 8254-3:2016 ISO 2016Paper and board Measurement of specular gloss Part 3: 20 gloss with a converging beam, TAPPI methodPapier e
5、t carton Mesurage du brillant spculaire Partie 3: Brillant 20 avec un faisceau convergent, mthode TAPPIINTERNATIONAL STANDARDISO8254-3Second edition2016-04-01Reference numberISO 8254-3:2016(E)BS ISO 8254-3:2016ISO 8254-3:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Pu
6、blished in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permi
7、ssion can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 8254-3:2016ISO 8254-3:2016(E)Fo
8、reword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Apparatus . 25.1 Gloss meter . 25.2 Gloss standards . 26 Sampling 47 Preparation of test pieces . 48 Calibration of the instrument . 49 Procedure. 410 Calculation and expression of results . 511 Test
9、report . 5Annex A (normative) Specification of the optical system of the gloss meter . 6Annex B (informative) Precision . 9Bibliography .10 ISO 2016 All rights reserved iiiContents PageBS ISO 8254-3:2016ISO 8254-3:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide
10、 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
11、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.The procedures used to develop this documen
12、t 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 accordance with the editorial rules of the ISO/IEC Directives,
13、 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. Details of any patent rights identified during the development o
14、f 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 endorsement.For an explanation on the meaning of ISO specific
15、 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 informationThe committee responsible for this document is ISO/TC 6, Paper, board and pul
16、ps.This second edition cancels and replaces the first edition (ISO 8254-3:2004), which has been editorially revised to provide a precision statement, to update the bibliographic references and to provide additional clarification on Scope and application of the method described in this International
17、Standard.ISO 8254 consists of the following parts, under the general title Paper and board Measurement of specular gloss: Part 1: 75 gloss with a converging beam, TAPPI method Part 2: 75 gloss with a parallel beam, DIN method Part 3: 20 gloss with a converging beam, TAPPI methodiv ISO 2016 All right
18、s reservedBS ISO 8254-3:2016ISO 8254-3:2016(E)IntroductionThis part of ISO 8254 deals with the assessment of the specular gloss of paper and board at an angle of 20, using a converging beam geometry commonly known as the TAPPI method and described in TAPPI T6532. ISO 8254-1 and ISO 8254-2 deal with
19、the measurement of specular gloss at 75.Although the word “measurement” is used, it is to be noted that this is strictly speaking only an “assessment” because the definition of gloss (see 3.1) relates to a scale of visual perception, whereas the method described uses a physical measurement of mixed
20、regular and diffuse reflection. The exact correlation between the visual perception and the scale established by the physical measurement is not known. However, this physical gloss scale has proved to be useful for a number of technical applications and, consequently, its standardization is justifie
21、d. ISO 2016 All rights reserved vBS ISO 8254-3:2016BS ISO 8254-3:2016Paper and board Measurement of specular gloss Part 3: 20 gloss with a converging beam, TAPPI method1 ScopeThis part of ISO 8254 specifies a method for measuring the specular gloss of paper and board at an angle of 20 to the normal
22、to the paper surface. It is applicable chiefly to highly glossy surfaces, such as cast-coated, lacquered, highly varnished or waxed papers and high-gloss ink films.NOTE This part of ISO 8254 has been developed from TAPPI T6532, ISO 28131and from ISO 8254-1.2 Normative referencesThe following documen
23、ts, in whole or in part, are normatively referenced in this document and are indispensable for its application. 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 Samp
24、ling to determine average qualityISO 187, Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1gloss (of a
25、surface)mode of appearance by which reflected highlights of objects are perceived as superimposed on the surface due to the directionally selective properties of that surfaceSOURCE: CIE S 017/E:2011, 17-50033.2regular reflectionspecular reflectionreflection in accordance with the laws of geometrical
26、 optics, without diffusionSOURCE: CIE S 017/E:2001, 17-107733.3diffuse reflectiondiffusion by reflection in which, on the macroscopic scale, there is no regular reflectionSOURCE: CIE S 017/E:2011, 17-30533.4specular glossmeasured variable equal to 100 times the ratio of the luminous flux reflected b
27、y the test-piece surface into a specified aperture at the specified angle of specular reflection to that reflected by a gloss standard specularly reflecting surface under the same conditionsINTERNATIONAL STANDARD ISO 8254-3:2016(E) ISO 2016 All rights reserved 1BS ISO 8254-3:2016ISO 8254-3:2016(E)4
28、PrincipleLight incident on the test-piece surface at an angle of 20 to the normal and reflected from the surface at an angle of 20 to the normal into a defined aperture is detected by a photodetector, the output of which is displayed on a meter. The gloss scale is established by reference to the ref
29、lection from a standard black glass of known refractive index. Annex B provides precision data.5 Apparatus5.1 Gloss meterIt has the general arrangement and relative dimensions of the principal parts described in Annex A. It consists of:a) a source of light;b) a lens giving a converging beam of light
30、 incident on the test piece;c) a suitable device, such as a suction plate to hold the test piece flat, if required;d) a photodetector to receive and measure certain of the rays reflected by the test piece.These components are combined in a light-tight housing that is matte black inside and is struct
31、urally and optically stable at the operating temperature.5.2 Gloss standards5.2.1 Primary gloss standard, a flat, clean and polished surface, having a refractive index of 1,540 at 587,6 nm (the helium D-line). This may be shown by the Fresnel formulae to measure 100 gloss units on a scale related to
32、 the theoretical primary gloss standard. The theoretical primary specular gloss standard is an ideal, completely reflecting plane mirror having an assigned gloss value of 2 199.45.2.2 High gloss reference standard, a clean plaque of polished black glass for which the 20 specular reflectance has been
33、 computed from its refractive index measured at a wavelength of 587,6 nm.If the refractive index differs from 1,540, the gloss value shall be calculated as follows:GK=100 (1)whereKnnnnn,()=()+()22052205cos sincos sin22+()()+2205205nnsincos sincos 22,()+22205221 540 1 5401 540 1 540,cos sincos 2 ssin
34、sincos 22()+()05220521 5401 540, ()+sincos 2052,(2)wheren is the refractive index of the glass; is the angle of incidence.2 ISO 2016 All rights reservedBS ISO 8254-3:2016ISO 8254-3:2016(E)When = 20, the formula reduces toKnnnnn,20 10 9940 939 701170 939 701172205220()=( )+( )522052050 117 0 939 70 1
35、17 0 939 7+( )( )+nn,2(3)NOTE 1 If the refractive index is known, the gloss value can be calculated by adding or subtracting from 100,0 a value of 0,29 for each 0,001 departure of the refractive index from the standard value of 1,540. For example, for a glass of refractive index n = 1,523, the assig
36、ned gloss value G would beGnn=10002915400 001290 346 6095 1(),(4)This method is, however, valid only for refractive index values between 1,50 and 1,54. It is not applicable to quartz standards for which n is about 1,46.NOTE 2 Commercial gloss meters with 20 gloss scales based on International Standa
37、rds with refractive index of 1,567 for general materials (paint, plastics, ceramics) will report different gloss readings for paper samples which are based on a refractive index of 1,540 and are not compatible with this part of ISO 8254.5.2.3 Intermediate gloss standards, having a reflected flux dis
38、tribution comparable with that of the paper to be tested. Such standards can consist of ceramic tiles which are sufficiently flat to remain stationary without rocking when placed in the measurement position and are uniform in gloss over a central region larger in area than the illuminated area defin
39、ed by Formulae (A.3) and (A.4). Each of these tiles shall be calibrated against the high gloss reference standard by a technically competent laboratory in an instrument conforming to 5.1.5.2.4 Working standards, having reflected flux distributions corresponding to different gloss levels, calibrated
40、in the instrument concerned against a range of intermediate gloss standards.Store standards in a closed container when not in use. Keep them away from any dirt which may scratch or mar their surfaces. Never place standards face down on a surface which may be dirty or abrasive. Always hold standards
41、by their side edges to avoid transferring oil from the skin to the standard surface. Clean standards in warm water and mild detergent solution, brushing gently with a soft nylon brush. (Do not use soap solutions to clean standards.) Rinse in hot running water (temperature near 65 C) to remove deterg
42、ent solution, followed by a final rinse in distilled water. Do not wipe intermediate gloss standards (5.2.3). The high gloss reference standard (5.2.2) may be dabbed gently with a lint-free paper towel or other lint-free absorbent material. Place rinsed standards in a warm oven to dry.The refractive
43、 index of the surface, and consequently the gloss value of the high gloss reference standard (5.2.2), might change slowly over a period of a few years. This could be accompanied by a loss of uniformity. It is recommended that this standard be sent to a technically competent laboratory at least once
44、every two years for a check on its calibration and for possible repolishing to restore its uniformity.55.3 Zero-gloss standard, consisting of a black velvet-lined cavity or any other suitable type of black cavity.NOTE A variety of suitable cavities are available, including those coated with a matte
45、black paint or having an interior black pyramidal construction. ISO 2016 All rights reserved 3BS ISO 8254-3:2016ISO 8254-3:2016(E)6 SamplingSampling is not included in this part of ISO 8254. If the mean quality of a lot is to be determined, sampling shall be carried out in accordance with ISO 186. I
46、f the tests are made on another type of sample, make sure that the test pieces are representative of the sample received.7 Preparation of test piecesAvoiding watermarks, dirt and obvious defects, cut at least five test pieces (10 pieces if both sides are to be measured) each of sufficient size to co
47、mpletely cover the test-piece opening of the instrument. Keep the test piece clean and do not handle the area to be tested. Condition the test pieces in an atmosphere at 23 C and 50 % relative humidity according to ISO 187.Exposure of paper to high humidity could irreversibly decrease the gloss. If
48、papers are tested at a relative humidity higher than 65 %, or if there is reason to believe that the sample might have been exposed to a relative humidity higher than 65 %, this should be stated in the test report.8 Calibration of the instrument8.1 Cover the test-piece opening with an opaque materia
49、l and, with the gloss-meter source turned off, check and adjust the zero of the meter. Turn on the source and, after a suitable warm-up period, insert the high gloss reference standard (5.2.2) and adjust the scale controls to give an instrument reading equal to the value of the gloss standard.8.2 Recheck the zero of the instrument
