1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58optical imaging Part 3: Evaluation of delamination and corrosion around a scribeThe European Standa
2、rd EN ISO 21227-3:2007 has the status of a British StandardICS 87.040Paints and varnishes Evaluation of defects on coated surfaces using BRITISH STANDARDBS EN ISO 21227-3:2007BS EN ISO 21227-3:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee
3、on 28 September 2007 BSI 2007ISBN 978 0 580 55275 5Amendments issued since publicationAmd. No. Date CommentsCompliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of EN ISO 21227-3:2007.The UK participation in
4、its preparation was entrusted to Technical Committee STI/10, Test methods for paints.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 necessary provisions of a contract. Users are responsible for it
5、s correct application.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 21227-3April 2007ICS 87.040English VersionPaints and varnishes - Evaluation of defects on coated surfacesusing optical imaging - Part 3: Evaluation of delamination andcorrosion around a scribe (ISO 21227-3:2007)Peintures et
6、vernis - valuation par imagerie optique desdfauts des surfaces revtues - Partie 3: valuation dudcollement et de la corrosion autour dune rayure (ISO21227-3:2007)Beschichtungsstoffe - Beurteilung vonBeschichtungsschden mittels digitaler Bildverarbeitung -Teil 3: Auswertung der von einem Ritz ausgehen
7、denEnthaftung und Korrosion (ISO 21227-3:2007)This European Standard was approved by CEN on 31 March 2007.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
8、. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
9、under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece,
10、 Hungary, Iceland, Ireland, Italy, 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 Centr
11、e: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 21227-3:2007: EForeword This document (EN ISO 21227-3:2007) has been prepared by Technical Committee ISO/TC 35 “Paints and varnishes“ in
12、collaboration with Technical Committee 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 October 2007, and conflicting nat
13、ional standards shall be withdrawn at the latest by October 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, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Fi
14、nland, France, Germany, Greece, Hungary, Iceland, 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 21227-3:2007 has been approved by CEN as EN IS
15、O 21227-3:2007 without any modifications. EN ISO 21227-3:2007Reference numberISO 21227-3:2007(E)INTERNATIONAL STANDARD ISO21227-3First edition2007-04-01Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 3: Evaluation of delamination and corrosion around a scribe
16、 Peintures et vernis valuation par imagerie optique des dfauts des surfaces revtues Partie 3: valuation du dcollement et de la corrosion autour dune rayure EN ISO 21227-3:2007ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle.
17、 1 5 Requirements 2 6 Calibration . 2 7 Procedure 2 8 Evaluation 3 9 Precision 4 10 Test report . 5 Annex A (normative) Ratings in accordance with ISO 4628-8 to be used to evaluate the delamination and corrosion around a scribe. 6 Annex B (informative) Extended evaluation 8 Bibliography . 9 EN ISO 2
18、1227-3:2007iv 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 subject
19、 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. International Standards are drafted in 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
21、 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 document may be the subject of patent rights. ISO shall not be hel
22、d responsible for identifying any or all such patent rights. ISO 21227-3 was prepared by Technical 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 Eval
23、uation of defects on coated surfaces using optical imaging: Part 1: General guidance Part 2: Evaluation procedure for multi-impact stone-chipping test Part 3: Evaluation of delamination and corrosion around a scribe EN ISO 21227-3:2007vIntroduction The conventional ISO test methods for evaluating su
24、rface defects and changes in appearance often utilize pictorial standards which depict particular types of surface deterioration and require human visual evaluation. The technology and procedures described in this part of ISO 21227 can yield more objective, accurate, quantitative and reproducible re
25、sults when compared to the human visual evaluation techniques. EN ISO 21227-3:2007blank1Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 3: Evaluation of delamination and corrosion around a scribe 1 Scope This part of ISO 21227 specifies a method for evaluatin
26、g delamination and corrosion around a scribe by means of digital optical imaging. The damaged surface can be produced in accordance with ISO 9227, ISO 11997-1 or ISO 11997-2. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated r
27、eferences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 4628-8, Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects, and of intensity of uniform changes
28、 in appearance Part 8: Assessment of degree of delamination and corrosion around a scribe ISO 21227-1, Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 1: General guidance 3 Terms and definitions For the purposes of this document, the terms and definitions giv
29、en in ISO 21227-1 and the following apply. 3.1 delaminated area area from which a paint or paint system has detached 3.2 corroded area substrate area from which a paint or paint system has detached and which has subsequently been attacked by corrosion 4 Principle A grey scale or colour image is prod
30、uced from the digital optical image of a surface damaged by delamination or corrosion around a scribe. In the simplest case, this image is converted into a binary image (thresholding). The damaged area is measured and the mean and maximum width of delamination or corrosion is determined. In addition
31、, the shape of the zone affected by delamination or corrosion around a scribe can be identified using digital optical imaging. EN ISO 21227-3:20072 5 Requirements 5.1 General The assessment shall be carried out under the conditions specified in ISO 21227-1. 5.2 Illumination The illumination shall be
32、 such that the damaged areas can be clearly distinguished from the undamaged areas. Because of the high contrast, corrosion can be easily recognized under diffused reflection illumination after stripping the coating. When detecting delamination without previously removing the coating, directional re
33、flection illumination can be of advantage because of the low contrast. 5.3 Resolution The minimum resolution shall be 6 pixels per millimetre. NOTE Different resolutions, in particular in the case of damage involving a large number of fissures, can lead to different values for the damaged areas. If
34、a resolution deviating from the resolution specified above is used, this shall be stated in the test report. 6 Calibration By adjusting the optical imaging system, it is possible to digitize a damaged area. By calibrating the scale in both X and Y directions (e.g. with graph paper graduated in milli
35、metres), the previously generated binary image can be measured with sufficient accuracy to obtain the width of the delamination or corrosion. When using a reference scale based on pictorial standards, calibration should be performed with these images. In this case, an interlaboratory test should be
36、conducted to determine the correlation between visual assessment and digital optical imaging. 7 Procedure Prepare the test panels for digital evaluation following the procedure given in ISO 4628-8. Using the previously calibrated digital optical imaging system, take a picture of the test panel area
37、containing the scribe and of the adjacent damaged area. After suitable threshold setting and detection, the digital image delivers a value for the damaged area including the area of the scribe. The scribe length on the assessed area shall also be determined. The start and end of the scribe and the c
38、orresponding damaged area are not assessed. If the test panel contains several scribes or zones to be assessed (e.g. two intersecting scribes), they may be treated as sections of a single scribe, and the relevant areas and scribe lengths may be added to one another. The area of intersection is not a
39、ssessed. If the scribe width is not known, it shall be measured. If the scribe width cannot be measured, it shall be set to the same value (preferably zero) for all comparative samples, and this value shall be quoted in the test report. EN ISO 21227-3:200738 Evaluation 8.1 General Unlike visual asse
40、ssment of delamination or corrosion area, digital optical imaging can directly determine the size of an area of any shape (see Figure 1); Ad, Ac, dmaxand cmaxare evaluated and d and c are then calculated. Consequently, subsequent assessments will be more precise and reproducible. Key Asarea of the s
41、cribe in the area of evaluation Adarea of delamination including the evaluated area of corrosion and area of the scribe Acarea of corrosion including the evaluated area of the scribe w width of the scribe l evaluated length of the scribe dmax, lmaximum width of delamination on the left side of the s
42、cribe dmax, rmaximum width of delamination on the right side of the scribe cmax, lmaximum width of corrosion on the left side of the scribe cmax, rmaximum width of corrosion on the right side of the scribe Figure 1 Image with all parameters required for assessment 8.2 Mean width of delamination or c
43、orrosion With the known scribe width w, calculate the scribe area As, using Equation (1): sA wl= (1) Calculate the mean delamination width d, in millimetres, using Equation (2): ds12AAdl= (2) EN ISO 21227-3:20074 Calculate the mean corrosion width c, in millimetres, as given in Equation (3): cs12AAc
44、l= (3) where Asis the evaluated scribe area in the area of evaluation, in square millimetres; Adis the evaluated area of delamination and corrosion, including the scribe area, in square millimetres; Acis the evaluated area of corrosion, including the scribe area, in square millimetres; l is the eval
45、uated scribe length, in millimetres. 8.3 Rating in accordance with ISO 4628-8 To allow comparison with the visual evaluation, the value determined through image evaluation from the width of the delaminated or corroded area around the scribe shall correspond to the numerical rating scale from 0 to 5
46、as specified in ISO 4628-8. The relationship between the width, in millimetres, and the numerical rating is given by Equation (4): 0,505 NR 0,409(or ) edc= or NR 0,81 1,98 ln (or )dc=+ (4) where d is the mean delamination width, in millimetres; c is the mean corrosion width, in millimetres; NR is th
47、e numerical rating (grade). For further details, see Annex A. 9 Precision In an interlaboratory test, seven samples with different degrees of delamination damage were assessed by six laboratories both visually and using different digital optical imaging systems. The relative standard deviation of th
48、e laboratories in determining the mean width of delamination from analysis of the damaged area was on average 9 % for all samples. The individual laboratories worked with different resolutions. The mean deviation of the visual assessment compared to digital image processing was 15 %. However, it sho
49、uld be noted that the mean relative standard deviation of the individual laboratories for the visual assessment was 31 %. Both procedures, visual assessment and digital optical imaging, ranked the samples in the same order for delamination width. The mean relative standard deviation of the individual laboratories for determining the shape of the delamination area, expressed as the standard deviation of 100 equidistantly spaced measurements of the delamination width, was 11 %. EN ISO 21227-3:2
