1、BRITISH STANDARD BS EN 29455-8:1993 ISO9455-8: 1991 Soft soldering fluxes Test methods Part 8: Determination of zinc content The European Standard EN29455-8:1993 has the status of a BritishStandard UDC 621.791.35.048:620.1:543.24:546.47BSEN29455-8:1993 This BritishStandard, having been prepared unde
2、r the directionof the Non-ferrous Metals Standards Policy Committee, was published underthe authority of the Standards Board and comesintoeffect on 15 December1993 BSI01-2000 The following BSI references relate to the work on this standard: Committee reference NFM/27 Draft for comment90/46342DC ISBN
3、 0 580 21833 3 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de norm
4、alisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Author
5、ity of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standa
6、rdiseringskommissionen i Sverige Switzerland Association suisse de normalisation UnitedKingdom BritishStandards Institution Amendments issued since publication Amd. No. Date CommentsBSEN29455-8:1993 BSI 01-2000 i Contents Page Cooperating organizations Inside front cover National foreword ii Forewor
7、d 2 1 Scope 3 2 Normative reference 3 3 Principle 3 4 Reagents 3 5 Apparatus 3 6 Procedure 3 7 Calculation of results 4 8 Precision 4 9 Test report 4 National annex NA (informative) Committees responsible Inside back coverBSEN29455-8:1993 ii BSI 01-2000 National foreword This BritishStandard has bee
8、n prepared under the direction of the Non-ferrous Metals Standards Policy Committee and is the English language version of EN29455-8:1993 Soft soldering fluxes Test methods Part8: Determination of zinc content published by the European Committee for Standardization (CEN). It is identical with ISO945
9、5-8:1991 published by the International Organization for Standardization (ISO). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself c
10、onfer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This
11、will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN29455-8 August1993 UDC 621.791.35.048:620.1:543.24:546.47 Descriptors: Soldering, soldering fluxes, chemical analysis, determination of content, zinc, volumetric analysis English ve
12、rsion Soft soldering fluxes Test methods Part8:Determinationof zinc content (ISO9455-8:1991) Flux de brasage tendre Mthodes dessai Partie8: Dosage du zinc (ISO9455-8:1991) Flumittel zum weichlten Prfverfahren Teil8: Bestimmung des Zinkgehaltes (ISO9455-8:1991) This European Standard was approved by
13、CEN on1993-08-02. 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 national standards ma
14、y 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 translation under the responsibility of a CEN member into its own language and notified to the Cen
15、tral Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European
16、Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1993 Copyright reserved to CEN members Ref. No. EN29455-8:1993 EEN29455-8:1993 2 BSI 01-2000 Foreword In1991, ISO9455-8:1991 Soft soldering fluxes Test
17、 methods Part8: Determination of Zinc content was submitted to the CEN Unique Acceptance Procedure. The result of the UAP was positive. 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 February1994
18、, and conflicting national standards shall be withdrawn at the latest by February1994. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxem
19、bourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom.EN29455-8:1993 BSI 01-2000 3 1 Scope This part of ISO9455 specifies a method for the determination of the zinc content of water soluble fluxes of type3, as defined in ISO9454-1. The method is intended to apply to
20、an aqueous solution of flux containing approximately25% of zinc, expressed as zinc chloride (ZnCl 2 ). For solid fluxes and for solutions whose concentrations differ appreciably from those stated above, an appropriate adjustment should be made to the amount of sample taken for the test. 2 Normative
21、reference The following standard contains provisions which, through reference in this text, constitute provisions of this part of ISO9455. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this part of ISO9455 are e
22、ncouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO9454-1:1990, Soft soldering fluxes Classification and requirements Part1:Classification, labelling an
23、d packaging. 3 Principle To an aqueous solution of the flux, containing sulfuric acid, ammonium chloride is added and the solution made alkaline by the addition of ammonia solution. Any precipitated iron is removed as hydroxide. The zinc content of the flux is determined by titrating the solution us
24、ing EDTA. 4 Reagents During the test use only reagents of recognized analytical quality and only distilled, or deionized, water. 4.1 Disodium dihydrogen ethylenediaminetetra-acetate solution (EDTA) standard volumetric solution, c(EDTA)=0,1mol/l. Dry approximately10g of disodium dihydrogen ethylenedi
25、aminetetra-acetate (C 10 H 14 N 2 Na 2 O 8 .2H 2 O) for2h at80 C. Dissolve9,308g of the dried salt in water, transfer to a250ml volumetric flask, dilute to the mark and mix well. NOTE 11ml of0,1mol/l EDTA solution is equivalent to0,00654g of zinc, or0,01363g of zinc chloride. 4.2 Buffer solution (pH
26、10) Dissolve7g of ammonium chloride (NH 4 Cl) in20ml of water. Add57ml of ammonia solution ( 0,91g/ml) and dilute to100ml. Mix well. 4.3 Sulfuric acid, 20% (V/V) solution Add cautiously, with stirring,200ml of sulfuric acid ( 1,84g/ml) to400ml of water and mix. Cool and dilute to1000ml and mix well.
27、 4.4 Eriochrome black T mixture Dissolve0,25g of eriochrome black T (also known as mordant black11 and solochrome black) and2,25g hydroxylammonium chloride in a mixture of45ml of water and5ml of triethanolamine. NOTE 2This solution should be freshly prepared from a recently purchased batch of erioch
28、rome black T. 4.5 Hydrochloric acid, 1,16g/ml or1,18g/ml. 4.6 Ascorbic acid 4.7 Ammonium chloride, (NH 4 Cl) 4.8 Ammonia solution, 0,91g/ml. 5 Apparatus Ordinary laboratory apparatus is required. 6 Procedure Carry out the following procedure in triplicate. By means of a pipette, transfer25,0ml of th
29、e flux sample to a500ml volumetric flask. NOTE 3This method is intended for flux samples containing approximately25% zinc in aqueous solution. For flux samples having a concentration appreciably different from this, make an appropriate adjustment to the volume of sample used for the test. Solid flux
30、es should be dissolved in water to give a flux sample having a zinc content around25%. Add10ml of sulfuric acid solution(4.3), dilute to the mark with water and mix well. By means of a pipette, transfer20,0ml of this solution to a250ml beaker, dilute to approximately100ml and add a few drops of hydr
31、ochloric acid(4.5). Add approximately10g of ammonium chloride(4.7) and make alkaline with ammonia solution(4.8). If iron is precipitated, boil the solution and filter it through a rapid filter paper, washing the precipitate well with water containing a few drops of ammonia solution(4.8). Combine the
32、 filtrate and washings and discard the precipitate. Add approximately0,2g of ascorbic acid(4.6) and15ml of buffer solution(4.2). Stir well and add dropwise sufficient eriochrome black T mixture(4.4) to produce a clearly visible red/purple colour. Titrate with the EDTA solution(4.1) to a blue end poi
33、nt. NOTE 4The end point of the titration is more easily detected if the progress of the titration is viewed using an incandescent light source.EN29455-8:1993 4 BSI 01-2000 7 Calculation of results The percentage, by mass, of zinc in the original flux sample, expressed as zinc chloride, is given by t
34、he following formula: NOTE 5If the original flux were in solid form, or if a different sample volume were used for the test (see clause6, note3), then a suitable adjustment will need to be made to the calculation formula. 8 Precision Tests were carried out on three fluxes containing zinc covering th
35、e range17% (m/m) to28% (m/m). Four laboratories took part in the tests and the estimates for precision data, expressed as a percentage of zinc chloride, were as follows: Standard deviations: 9 Test report The test report shall include the following information: a) the identification of the test samp
36、le; b) the test method used (i.e.reference to this part of ISO9455); c) the results obtained; d) any unusual features noted during the determination; e) details of any operation not included in this part of ISO9455, or regarded as optional. where V is the volume, in millilitres, of EDTA solution(4.1
37、) used; d is the density, in grams per millilitre, of the original flux sample at20 C, determined by the use of a hydrometer. 1,363 V d - within laboratory s w 0,24 between laboratories s b 0,30 Repeatability r 0,66 Reproducibility R 0,84BSEN29455-8:1993 BSI 01-2000 National annex NA(informative) Co
38、mmittees responsible The UnitedKingdom participation in the preparation of this European Standard was entrusted by the Non-ferrous Metals Standards Policy Committee (NFM/-) to Technical Committee NFM/27 upon which the following bodies were represented: Association of British Pewter Craftsmen British
39、 Plumbing Fittings Manufacturers Association British Steel Industry Department of Trade and Industry EEA (The Association of Electronics, Telecommunications and Business Equipment Industries) International Tin Research Institute London Metal Exchange Metal Packaging Manufacturers Association Ministr
40、y of Defence Solder Makers AssociationBS EN 29455-8:1993 ISO9455-8: 1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international le
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