1、BRITISH STANDARDBS EN ISO 21227-2:2006Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 2: Evaluation procedure for multi-impact stone-chipping testThe European Standard EN ISO 21227-2:2006 has the status of a British StandardICS 87.040g49g50g3g38g50g51g60g44g4
2、9g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 21227-2:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee
3、on 31 August 2007 BSI 2007ISBN 978 0 580 57804 5National forewordThis British Standard is the UK implementation of EN ISO 21227-2:2006. The UK participation in its preparation was entrusted to Technical Committee STI/10, Test methods for paints.A list of organizations represented on this committee c
4、an be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAm
5、d. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 21227-2September 2006ICS 87.040English VersionPaints and varnishes - Evaluation of defects on coated surfacesusing optical imaging - Part 2: Evaluation procedure for multi-impact stone-chipping test (ISO 21227-2:2006)Peintures
6、 et vernis - valuation par imagerie optique desdfauts des surfaces revtues - Partie 2: Mode opratoiredvaluation pour lessai dimpacts multiples de cailloux(ISO 21227-2:2006)Beschichtungsstoffe - Beurteilung vonBeschichtungsschden mittels digitaler Bildverarbeitung -Teil 2: Auswertung der Multisteinsc
7、hlag-Prfung (ISO21227-2:2006)This European Standard was approved by CEN on 19 August 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lis
8、ts and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsi
9、bility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, It
10、aly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050
11、Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 21227-2:2006: EForeword This document (EN ISO 21227-2:2006) has been prepared by Technical Committee ISO/TC 35 “Paints and varnishes“ in collaboration with Technical C
12、ommittee CEN/TC 139 “Paints and varnishes“, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2007, and conflicting national standards shall be withdra
13、wn at the latest by March 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ice
14、land, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 21227-2:2006 has been approved by CEN as EN ISO 21227-2:2006 without any modifications. EN
15、 ISO 21227-2:2006Reference numberISO 21227-2:2006(E)INTERNATIONAL STANDARD ISO21227-2First edition2006-09-01Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 2: Evaluation procedure for multi-impact stone-chipping test Peintures et vernis valuation par imagerie
16、 optique des dfauts des surfaces revtues Partie 2: Mode opratoire dvaluation pour lessai dimpacts multiples de cailloux EN ISO 21227-2:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Principle. 1 4 Requirements 1 5 Calibration . 2 6 Procedure 2 7 Evaluatio
17、n 3 8 Precision 3 9 Test report . 4 Annex A (normative) Ratings in accordance with ISO 20567-1 to be used to evaluate the damage as a whole 5 Annex B (informative) Example of an extended evaluation. 7 EN ISO 21227-2:2006iv Foreword ISO (the International Organization for Standardization) is a worldw
18、ide 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 th
19、at 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
20、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 r
21、equires 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 21227-2 was prepared by Te
22、chnical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9, General test methods for paints and varnishes. ISO 21227 consists of the following parts, under the general title Paints and varnishes Evaluation of defects on coated surfaces using optical imaging: Part 1: General guidance Part 2
23、: Evaluation procedure for multi-impact stone-chipping test Part 3: Evaluation of delamination and corrosion around a scribe EN ISO 21227-2:2006vIntroduction The conventional ISO test methods for evaluating surface defects and appearance changes often utilize pictorial standards which depict particu
24、lar types of surface deterioration and require human visual evaluation. The technology described in this part of ISO 21227 can yield more objective, accurate, quantitative and reproducible results when compared to the human visual evaluation techniques. EN ISO 21227-2:2006blank1Paints and varnishes
25、Evaluation of defects on coated surfaces using optical imaging Part 2: Evaluation procedure for multi-impact stone-chipping test 1 Scope This part of ISO 21227 describes a procedure for evaluating multi-stone impact damage by means of optical imaging. A suitable method for simulating the damaging pr
26、ocess is specified in ISO 20567-1. 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)
27、applies. ISO 20567-1, Paints and varnishes Determination of stone-chip resistance of coatings Part 1: Multi-impact testing ISO 21227-1, Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 1: General guidance 3 Principle From a digital optical image of the degrada
28、tion caused by stone chipping, a grey-scale or colour image is made. This image is transformed into a binary image (through thresholding) in which the damaged areas of the surface are shown as black patches while the undamaged areas of the surface are visible as white patches. The percentage of the
29、damaged to the total test area is recorded and a rating determined. 4 Requirements 4.1 General The conditions specified in ISO 21227-1 apply to this part of ISO 21227 as well. 4.2 Illumination The illumination shall be such that the damaged areas can be clearly distinguished from the undamaged areas
30、. Experience has shown that diffuse bright-field illumination is suitable for image acquisition of multi-impact degradation. NOTE If direct illumination is used, any kind of surface disturbance which is not caused by stone chipping can also be detected. EN ISO 21227-2:20062 4.3 Region of interest an
31、d resolution The size of the region of interest (ROI) of the image should preferably be 70 mm 70 mm. When the test is performed using smaller ROIs, for example because these are easier to illuminate, it shall be ensured that the difference between the result of the evaluation of the reference area a
32、nd that of the evaluation of the total area is not larger than half a rating as defined in ISO 20567-1. NOTE 1 The ROI size of 70 mm 70 mm was chosen to exclude regions of uneven distribution of damage at the edges of the area of 80 mm 80 mm previously used. NOTE 2 The result of the evaluation of a
33、smaller ROI can be considerably different from evaluation of the total area. The minimum resolution shall be 6 pixels per millimetre. NOTE 3 Different resolutions can lead to different values for the damaged areas. 5 Calibration 5.1 General The purpose of the calibration process is to fix the image
34、acquisition parameters in such a way that image analysis will make it possible to assign the right rating to test panels that have not been examined before, by using ratings that have been determined for reference panels in accordance with ISO 20567-1. Furthermore, a visual comparison is made to ver
35、ify the correspondence between the reference panel and the digitized image with regard to the detected degradation. This calibration procedure guarantees only the repeatability of the process; for the reproducibility, refer to Clause 8. The reference panels shall be as similar as possible to the tes
36、t panels as far as the structure and contrast of the individual layers are concerned; they shall therefore be prepared in the same laboratory, using the same equipment. 5.2 Calibration process Carry out the calibration process as described below using a self-made set of reference panels to which the
37、 ratings defined in ISO 20567-1 (see Annex A) have been assigned and which cover the whole range of these ratings. Take a picture of the impact area of each reference using the selected optical-imaging system. Visually compare each digitized image with the corresponding reference panel to determine
38、whether the damaged and undamaged areas correspond to those on the reference panel. If so, analyse the image using the optical-imaging system. The result of this analysis shall represent the rating for each reference panel. If calibration is not possible although the settings of all the system compo
39、nents involved in the image acquisition process have been optimized, the selected optical-imaging system is not suitable for the evaluation to be made. NOTE The results of optical imaging and visual evaluation can differ since visual evaluation unconsciously considers not only the damaged area but a
40、lso additional characteristics, e.g. the size and distribution of the defects. 6 Procedure Prepare the test panels for optical imaging following the procedure specified in ISO 20567-1. Create an image of the test panel using the calibrated optical-imaging system. Once suitable threshold values have
41、been established, the digitized image provides, on analysis, a value for the damaged area. To ensure optimum results, the difference between the test panels and the reference panels shall not be too big. EN ISO 21227-2:200637 Evaluation 7.1 General The result of the image analysis is a data recordin
42、g to which one or more ratings are assigned. 7.2 Evaluation If the coating is delaminated or flaked, all such damage shall be included in the evaluation, irrespective of which layer it occurs in. NOTE This type of damage can also occur on soft substrates, such as plastics or aluminium. 7.3 Rating in
43、 accordance with ISO 20567-1 Determine the percentage of the total evaluated area represented by the damaged area, the damaged and undamaged areas together making up 100 %. The damaged areas shall be those visible in the image as discrete black- or grey-shaded patches, while the undamaged areas shal
44、l be those which appear white. To allow comparison with the visual evaluation, the percentage damaged area determined through image evaluation shall be expressed as a rating on the rating scale from 0 to 5,0 as specified in ISO 20567-1. Results that fall between two whole numbers shall be expressed
45、as half-point ratings such as 3,5. 7.4 Extended evaluation For an extended evaluation, the contributions of the individual layers to the total damaged area can be determined. The layer that accounts for the largest share of the damaged area shall be regarded as the main separation level. If possible
46、, the extent of individual areas of damage and the percentage of the total area represented by each such area shall be determined. The data compiled in this way can be used as the basis for a number of further analyses. An example of an extended evaluation is given in Annex B. 8 Precision In 2003, I
47、SO/TC 35/SC 9 carried out an international round-robin test in which nine laboratories from four countries participated. Two test panels were used, each containing two areas of stone-chip damage, created in accordance with ISO 20567-1. Different digital optical-imaging technologies were used for the
48、 evaluation of a region of interest of 70 mm 70 mm, all using diffuse bright-field illumination. The repeatability limit, r, was not determined. The reproducibility limit, R, was determined for two different levels of damage. The results are given in Table 1. Table 1 Reproducibility limit Damaged ar
49、ea Rating in accordance with ISO 20567-1 Reproducibility standard deviation, sRReproducibility limit, R % % % 3,2 1,5 0,6 1,6 6,3 2 1,1 3,0 EN ISO 21227-2:20064 9 Test report The test report shall contain at least the following information: a) all information necessary for identification of the coating tested (manufacturer, trade name, batch number, etc.); b) a reference to this part of ISO 21227 (ISO 21227-2:2006); c) the type of illumination (light source, arrangement of lamps); d) the image-acquisition set-up used, includin
