1、July 2007DEUTSCHE NORM English price group 9No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 87.040!,ye?“9866628www.din
2、.deDDIN EN ISO 21227-3Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 3: Evaluation of delamination and corrosion around a scribe(ISO 21227-3:2007)English version of DIN EN ISO 21227-3:2007-07Beschichtungsstoffe Beurteilung von Beschichtungsschden mittels dig
3、italer Bildverarbeitung Teil 3: Auswertung der von einem Ritz ausgehenden Enthaftung und Korrosion(ISO 21227-3:2007)Englische Fassung DIN EN ISO 21227-3:2007-07www.beuth.deDocument comprises 15 pages 10.07DIN EN ISO 21227-3:2007-07 2 National foreword This standard falls within the responsibility of
4、 Technical Committee CEN/TC 139 “Paints and varnishes” (Secretariat: DIN, Germany). It is identical with International Standard ISO 21227-3:2007, which was prepared by Technical Committee ISO/TC 35 “Paints and varnishes”, Subcommittee SC 9 “General test methods for paints and varnishes” (Secretariat
5、: BSI, United Kingdom). The responsible German body involved in its preparation was the Normenausschuss Beschichtungsstoffe und Beschichtungen (Coatings and Coating Materials Standards Committee), Technical Committee NA 002-00-07 AA Allgemeine Prfverfahren fr Beschichtungsstoffe und Beschichtungen.
6、DIN EN 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: Evaluation procedure for multi-impact stone-chipping test Part 3: Evaluation of delamination and corrosion a
7、round a scribe Part 4: Evaluation of filiform corrosion (draft standard) The DIN Standards corresponding to the International Standards referred to in clause 2 and in the bibliography of the EN are as follows: ISO 4628-8 DIN EN ISO 4628-8 ISO 9227 DIN EN ISO 9227 ISO 11997-1 DIN EN ISO 11997-1 ISO 1
8、1997-2 DIN EN ISO 11997-2 ISO 21227-1 DIN EN ISO 21227-1 National Annex NA (informative) Bibliography DIN EN ISO 4628-8, Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects, and of intensity of uniform changes in appearance Part 8: Assessment of deg
9、ree of delamination and corrosion around a scribe DIN EN ISO 9227, Corrosion tests in artificial atmospheres Salt spray tests DIN EN ISO 11997-1, Paints and varnishes Determination of resistance to cyclic corrosion conditions Part 1: Wet (salt fog)/dry/humidity DIN EN ISO 11997-2, Paints and varnish
10、es Determination of resistance to cyclic corrosion conditions Part 2: Wet (salt fog)/dry/humidity/UV light DIN EN ISO 21227-1, Paints and varnishes Evaluation of defects on coated surfaces using optical imaging Part 1: General guidance EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 21227-3
11、 April 2007 ICS 87.040 English Version Paints and varnishes - Evaluation of defects on coated surfaces using optical imaging - Part 3: Evaluation of delamination and corrosion around a scribe (ISO 21227-3:2007) Peintures et vernis - valuation par imagerie optique des dfauts des surfaces revtues - Pa
12、rtie 3: valuation du dcollement et de la corrosion autour dune rayure (ISO 21227-3:2007) Beschichtungsstoffe - Beurteilung von Beschichtungsschden mittels digitaler Bildverarbeitung - Teil 3: Auswertung der von einem Ritz ausgehenden Enthaftung und Korrosion (ISO 21227-3:2007) This European Standard
13、 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 European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such
14、national standards 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 under the responsibility of a CEN member into its own language
15、and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembo
16、urg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All righ
17、ts of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 21227-3:2007: EContents Page Introduction 1 Scope . 2 Normative references . 3 Terms and definitions. 4 Principle. 5 Requirements 6 Calibration . 7 Procedure 8 Evaluation 9 Precision 10 Test
18、report . Annex A (normative) Ratings in accordance with ISO 4628-8 to be used to evaluate the 2 EN ISO 21227-3:2007 (E)455566678910 1213Foreword . 35delamination and corrosion around a scribe. Annex B (informative) Extended evaluation Bibliography .Foreword This document (EN ISO 21227-3:2007) has be
19、en prepared by Technical Committee ISO/TC 35 “Paints and varnishes” in 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 tex
20、t or by endorsement, at the latest by October 2007, and conflicting national 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: A
21、ustria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsemen
22、t notice The text of ISO 21227-3:2007 has been approved by CEN as EN ISO 21227-3:2007 without any modifications. 3 EN ISO 21227-3:2007 (E)Introduction The conventional ISO test methods for evaluating surface defects and changes in appearance often utilize pictorial standards which depict particular
23、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 results when compared to the human visual evaluation techniques. 4 EN ISO 21227-3:2007 (E)1 Scope Th
24、is part of ISO 21227 specifies a method for evaluating 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 indispensa
25、ble 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) applies. ISO 4628-8, Paints and varnishes Evaluation of degradation of coatings Designation of quantity and
26、 size of defects, and of intensity of uniform changes 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 pur
27、poses of this document, the terms and definitions given 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 corro
28、sion 4 Principle A grey scale or colour image is produced 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
29、 delamination or corrosion is determined. In addition, the shape of the zone affected by delamination or corrosion around a scribe can be identified using digital optical imaging. 5 EN ISO 21227-3:2007 (E)5 Requirements 5.1 General The assessment shall be carried out under the conditions specified i
30、n ISO 21227-1. 5.2 Illumination The illumination shall be 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 delaminatio
31、n without previously removing the coating, directional reflection 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
32、, can lead to different values for the damaged areas. If 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 a
33、nd Y directions (e.g. with graph paper graduated in millimetres), 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
34、 images. In this case, an interlaboratory test should be 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 optic
35、al imaging system, take a picture of the test panel area 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
36、 be determined. The start and end of the scribe and the corresponding 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 b
37、e added to one another. The area of intersection is not assessed. 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. 6 EN I
38、SO 21227-3:2007 (E)8 Evaluation 8.1 General Unlike visual assessment 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 assessme
39、nts will be more precise and reproducible. Key Asarea of the scribe 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
40、dmax, lmaximum width of delamination on the left side of the scribe 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 paramete
41、rs required for assessment 8.2 Mean width of delamination or corrosion 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) 7 EN ISO 21227-3:2007 (E)Calculate the mean co
42、rrosion width c, in millimetres, as given in Equation (3): cs12AAcl= (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 corrosio
43、n, including the scribe area, in square millimetres; l is the evaluated 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
44、scribe shall correspond to the numerical rating scale from 0 to 5 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 mi
45、llimetres; c is the mean corrosion width, in millimetres; NR is the 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 digi
46、tal optical imaging systems. The relative standard deviation of the 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 assessm
47、ent compared to digital image processing was 15 %. However, it should 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 delamin
48、ation 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 %. 8 EN ISO 21227-3:2007 (E)The precision of the method
49、specified in this part of ISO 21227 can be considered to be much higher for determining both the width of delamination and the shape of the delamination area than the precision observed in the interlaboratory test, because some sources of error (different resolution, assessment at the scribe ends, etc.) are avoided in this method. 10 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 numb
