1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 2376:2010Anodizing of aluminium andits alloys Determination ofelectric breakdown potential(ISO 2376:2010)BS EN ISO 2376:2010 BRITISH STANDARDNational forewordThis Briti
2、sh Standard is the UK implementation of EN ISO 2376:2010.It supersedes BS EN 12373-17:2001 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee STI/32, Anodic oxidation coatings on aluminium.A list of organizations represented on this committee can beobtaine
3、d on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 66004 7ICS 25.220.20; 77.120.10Compliance with a British Standard cannot confer immunity fromlegal obligation
4、s.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2010.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 2376 August 2010 ICS 25.220.20 Supersedes EN 12373-17:2001English V
5、ersion Anodizing of aluminium and its alloys - Determination of electric breakdown potential (ISO 2376:2010) Anodisation de laluminium et de ses alliages - Dtermination de la tension lectrique de claquage (ISO 2376:2010) Anodisieren von Aluminium und Aluminiumlegierungen - Bestimmung der elektrische
6、n Durchschlagspannung (ISO 2376:2010) This European Standard was approved by CEN on 14 July 2010. 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
7、-date lists and bibliographical references concerning such 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 unde
8、r the responsibility of a CEN member into its own language 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, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany,
9、 Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, 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 Man
10、agement Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 2376:2010: EBS EN ISO 2376:2010ISO 2376:2010(E) ISO 2010 All rights reserved iiiForeword ISO (the International Organization
11、 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 has been established has
12、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 electrotechnical standardization. Intern
13、ational 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 are circulated to the member bodies for voting. Publicati
14、on 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 held responsible for identifying any or all such patent right
15、s. ISO 2376 was prepared by Technical Committee ISO/TC 79, Light metals and their alloys, Subcommittee SC 2, Organic and anodic oxidation coatings on aluminium. This second edition cancels and replaces the first edition (ISO 2376:1972), which has been technically revised. BS EN ISO 2376:2010BS EN IS
16、O 2376:2010INTERNATIONAL STANDARD ISO 2376:2010(E) ISO 2010 All rights reserved 1Anodizing of aluminium and its alloys Determination of electric breakdown potential 1 Scope This International Standard specifies test methods for the determination of the electric breakdown potential of anodic oxidatio
17、n coatings on aluminium and its alloys, on flat or near-flat surfaces and on round wire. The methods are applicable to anodic oxidation coatings used primarily as electrical insulators. The methods are not applicable to coatings in the vicinity of cut edges, the edges of holes, or sharp changes of a
18、ngle on, for example, extruded shapes. NOTE 1 The methods described do not give satisfactory results for unsealed coatings. NOTE 2 Electric breakdown potential is affected by relative humidity. 2 Principle The electric voltage at which current first passes through an anodic oxidation coating is meas
19、ured; this breakdown potential is a function of the dielectric characteristics and the insulation properties of the oxidation coatings. The breakdown potential depends upon the thickness of the coating, as well as on many other factors, particularly the composition of the basis metal, its surface co
20、ndition, the effectiveness of sealing, the dryness of the sample and the degree of ageing. 3 Apparatus 3.1 Power supply, from a suitable 50 Hz or 60 Hz source. 3.2 Transformer (a.c.), having an output with a waveform as nearly sinusoidal as possible, capable of producing the potential required. 3.3
21、Voltage regulator, enabling the test potential to be increased gradually from any point without interruption, and providing an essentially undistorted waveform so that the peak potential is within the limit 2 5 % (i.e. 1,34 to 1,48) of the root-mean-square (r.m.s.) potential. 3.4 Current limiting re
22、sistor, 0,5 M, in series with secondary winding of the transformer and the test electrode probe (3.6). 3.5 Potential-measuring device, which gives r.m.s. values, expressed in volts. 3.6 Electrode probe, made from conducting material, suitably insulated for handling purposes, free to move as required
23、 and adequately supported. The contact surface shall be spherical with a diameter of 3 mm to 8 mm and shall be maintained in a smooth, untarnished condition. The design of the probe shall be such that, when the spherical surface is placed on the surface of the anodized test specimen, the total force
24、 exerted on the coating is 0,5 N to 1,0 N (a probe of mass 50 g to 100 g is suitable). BS EN ISO 2376:2010ISO 2376:2010(E) 2 ISO 2010 All rights reserved3.7 Contact plate, for testing flat test specimens, having a smooth, bright, metallic surface, or a contact probe or clip which is capable of break
25、ing through to the basis metal (see 4.2.1). 3.8 Twisting machine, for testing round wire, having two sets of jaws 400 mm apart, with one set of jaws fixed, while the other set is free to rotate. The jaws shall be mounted so as to prevent lateral movement of the jaws when the twisting operation is ca
26、rried out (see 4.2.2). 4 Procedure 4.1 Test specimen The test specimen shall normally consist of a production component (or a part thereof). It shall be sealed, dry and clean and, if required, shaped to correspond to its ultimate use in service. Unsealed items may be tested but only under conditions
27、 of known, recorded and controlled relative humidity. NOTE The use of specially prepared test specimens, processed at the same time and in the same manner as production articles, can lead to erroneous results. 4.2 Determination 4.2.1 Flat or near-flat surfaces Unless otherwise specified, carry out t
28、he determination at room temperature. Measure and record the relative humidity of the environment in which the test is taking place. Place the test specimen on the contact plate (3.7) in good electrical contact with it, for example by using an earthing clip. Alternatively, make contact to the basis
29、metal using the contact probe or clip. Connect the contact plate or contact probe or clip (3.7) and the electrode probe (3.6) to opposite poles of the secondary winding of the transformer (3.2), and place the probe on the test specimen so that the force exerted on the coating is 0,5 N to 1,0 N (see
30、3.6). Starting at zero, increase the potential uniformly at a rate not exceeding 25 V/s until the specified potential is reached or the potential drops suddenly (indicating electric breakdown of the coating). It is necessary to clean the contact surface of the probe after any breakdown has occurred,
31、 and it is essential to return the potential to zero after each determination and particularly before cleaning the probe. Carry out a minimum of five tests and record the lowest value and the mean value obtained. Alternatively, ascertain whether or not any value falls below a predetermined electric
32、breakdown potential. 4.2.2 Round wire Unless otherwise specified, carry out the determination at room temperature. Measure and record the relative humidity of the environment in which the test is taking place. Twist together two suitable lengths of wire using the twisting machine (3.8) so that the n
33、umber of twists per 50 mm specified in Table 1 is achieved. Ensure that the two lengths of wire are of equal length between the jaws, are under equal tension and are touching in the jaws. Remove the wires from the twisting machine, separate the wires for about 50 mm at each end, and remove the anodi
34、c coating from one pair of ends. Join the opposite poles of the secondary winding of the transformer to these exposed ends. BS EN ISO 2376:2010ISO 2376:2010(E) ISO 2010 All rights reserved 3Table 1 Number of twists for round wire test specimens Diameter of wire, d mm Number of twists per 50 mm 0,2 u
35、 d u 0,3 0,3 d u 0,5 0,5 d u 0,75 0,75 d u 1,25 1,25 d u 3,25 3,25 d u 6,5 5 4 3 2 1 0,5 Starting at zero, increase the potential uniformly at a rate not exceeding 25 V/s until the specified potential is reached or the potential drops suddenly (indicating electric breakdown of the coating). It is es
36、sential to return the potential to zero after each determination, and to maintain the contacts between the transformer and test specimen. Carry out a minimum of five tests and record the lowest value and the mean value obtained. Alternatively ascertain whether or not any value falls below a predeter
37、mined electric breakdown potential. 5 Expression of results Express the electric breakdown potential, in volts, as the lowest value recorded and the mean value. 6 Test report The test report shall include at least the following information: a) a reference to this International Standard; b) the type
38、and identification of the product tested; c) the anodizing specification, when applicable; d) the electric breakdown potential (see Clause 5) and, where appropriate, a statement as to whether the electric breakdown potential conformed to that specified for the product; NOTE The minimum acceptable br
39、eakdown potential will normally be specified in the relevant product specification. e) the relative humidity of the environment at the time of the test; f) any other relevant information on the tests or the results, including the test temperature, if it is different from room temperature; g) the dat
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