DIN EN ISO 11426-2016 Jewellery - Determination of gold in gold jewellery alloys - Cupellation method (fire assay) (ISO 11426 2014 Corrected version 2014-12-15) German version EN I.pdf

1、December 2016 English price group 9No part of this translation 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 39.060!%x“2599185www.din.deDIN E

2、N ISO 11426Jewellery Determination of gold in gold jewellery alloys Cupellation method (fire assay) (ISO 11426:2014, Corrected version 20141215);English version EN ISO 11426:2016,English translation of DIN EN ISO 11426:2016-12Schmuck Bestimmung von Gold in Goldschmucklegierungen Dokimastisches Verfa

3、hren (ISO 11426:2014, korrigierte Fassung 20141215);Englische Fassung EN ISO 11426:2016,Englische bersetzung von DIN EN ISO 11426:2016-12Joaillerie Dosage de lor dans les alliages dor pour la bijouteriejoaillerie Mthode de coupellation (essai au feu) (ISO 11426:2014, Version corrige 20141215);Versio

4、n anglaise EN ISO 11426:2016,Traduction anglaise de DIN EN ISO 11426:2016-12SupersedesDIN EN ISO 11426:199910www.beuth.deDocument comprises 14 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.12.16 DIN EN ISO 11426:2016-12 2 A c

5、omma is used as the decimal marker. National foreword The text of ISO 11426:2014, corrected version 2014-12-15, has been prepared by Technical Committee ISO/TC 174 “Jewellery (Secretariat: DIN, Germany) and has been taken over as EN ISO 11426:2016 according to the decision CEN/BT C137/2015. The resp

6、onsible German body involved in its preparation was DIN-Normenausschuss Feinmechanik und Optik (DIN Standards Committee Optics and Precision Mechanics), Working Committee NA 027-04-04 AA Analysenmethoden. The DIN Standard corresponding to the International Standard referred to in this document is as

7、 follows: ISO 9202 DIN EN ISO 9202 Amendments This standard differs from DIN EN ISO 11426:1999-10 as follows: a) a note has been included in the scope that the method described in this standard is intended to be used as the recommended method; b) the requirement for sampling has been changed in Clau

8、se 6; c) a warning has been added in Clause 7 that suitable health and safety procedures should be followed; d) red gold alloys have been included in Subclause 7.2; e) in Subclause 7.3.1, requirements for white gold alloys containing nickel and palladium have been included; f) the standard has been

9、editorially revised. Previous editions DIN EN 31426: 1994-09 DIN EN ISO 11426: 1999-10 National Annex NA (informative) Bibliography DIN EN ISO 9202, Jewellery Fineness of precious metal alloys EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11426 October 2016 ICS 39.060 Supersedes EN ISO 11

10、426:1998English Version Jewellery - Determination of gold in gold jewellery alloys -Cupellation method (fire assay) (ISO 11426:2014) Joaillerie - Dosage de lor dans les alliages dor pour la bijouterie-joaillerie - Mthode de coupellation (essai au feu) (ISO 11426:2014) Schmuck - Bestimmung von Gold i

11、n Goldschmucklegierungen - Dokimastisches Verfahren (ISO 11426:2014) This European Standard was approved by CEN on 2 October 2017. 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 stand

12、ard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in an

13、y other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Repu

14、blic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN

15、 COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11426:2016 ECont

16、ents PageForeword .4Introduction 51 Scope . 62 Normative references 63 Principle 64 Reagents 65 Apparatus . 76 Sampling 87 Procedure. 87.1 General . 87.2 Yellow and red gold alloys, free of nickel, and palladium white gold alloys 87.2.1 Assay sample . 87.2.2 Proof assay samples 87.2.3 Cupellation an

17、d treatment of precious metal buttons 87.2.4 Parting of the silver/gold samples . 87.3 White gold alloys containing nickel 97.3.1 General 97.3.2 Cupellation with additional lead 97.3.3 Scorification . 97.4 White gold alloys containing palladium .107.5 Gold alloys incorporating more than 40 % silver

18、107.6 Alloys containing 999 gold108 Calculation and expression of results 108.1 Proof assay sample factor .108.2 Calculation of gold content 118.3 Repeatability 119 Test report 11Bibliography .12EN ISO 11426:2016 (E) DIN EN ISO 11426:2016-12 2European foreword .3European foreword The text of ISO 114

19、26:2014 has been prepared by Technical Committee ISO/TC 174 “Jewellery” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 11426:2016. This European Standard shall be given the status of a national standard, either by publication of an identical text or by

20、endorsement, at the latest by April 2017, and conflicting national standards shall be withdrawn at the latest by April 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for iden

21、tifying any or all such patent rights. This document supersedes EN ISO 11426:1998. 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, Croatia, Cyprus, Czech Repu

22、blic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endo

23、rsement notice The text of ISO 11426:2014 has been approved by CEN as EN ISO 11426:2016 without any modification. EN ISO 11426:2016 (E) DIN EN ISO 11426:2016-12 3 ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodie

24、s). 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 that committee. International organizations, governmental and n

25、on-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.The procedures used to develop this document and those intended for its further maintenance are descr

26、ibed in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to

27、 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. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the I

28、SO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as

29、 well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information .The committee responsible for this document is ISO/TC 174, Jewellery.This third edition cancels and replaces the second edition (ISO 11

30、426:1997), which has been technically revised with the following changes: change in the scope that this method is the referee method; change of requirement for sampling in Clause 6; addition of a warning in Clause 7 that suitable health and safety procedures should be followed; addition of red gold

31、alloys in 7.2; addition of requirements in 7.3.1 for white gold alloys containing nickel and palladium; standard editorially revised.This corrected version of ISO 11426:2014 incorporates the following correction: In 4.5, first dash: change of the value “999,99” into “999,9”.EN ISO 11426:2016 (E) DIN

32、 EN ISO 11426:2016-12 4 IntroductionThe following definitions apply in understanding how to implement an ISO International Standard and other normative ISO deliverables (TS, PAS, IWA). “shall” indicates a requirement “should” indicates a recommendation “may” is used to indicate that something is per

33、mitted “can” is used to indicate that something is possible, for example, that an organization or individual is able to do somethingISO/IEC Directives, Part 2 (sixth edition, 2011), 3.3.1 defines a requirement as an “expression in the content of a document conveying criteria to be fulfilled if compl

34、iance with the document is to be claimed and from which no deviation is permitted.”ISO/IEC Directives, Part 2 (sixth edition, 2011), 3.3.2 defines a recommendation as an “expression in the content of a document conveying that among several possibilities one is recommended as particularly suitable, w

35、ithout mentioning or excluding others, or that a certain course of action is preferred but not necessarily required, or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited.”EN ISO 11426:2016 (E) DIN EN ISO 11426:2016-12 5 1 ScopeThis International S

36、tandard specifies a cupellation method (fire assay) for the determination of gold in gold jewellery alloys. The gold content of the alloys should preferably lie between 333 and 999 parts per thousand ().The procedure is applicable specifically to gold alloys incorporating silver, copper, and zinc. S

37、ome modifications are indicated where nickel and/or palladium are present in the so-called white gold alloys, as well as for alloys containing 990 or more parts per thousand () of gold.This International Standard is intended to be used as the recommended method for the determination of fineness in a

38、lloys covered by ISO 9202.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docu

39、ment (including any amendments) applies.ISO 11596, Jewellery Sampling of precious metal alloys for and in jewellery and associated products3 PrincipleThe gold alloys are inquarted with silver, compounded with lead, and cupelled in a cupellation furnace until a precious metal button is obtained. Afte

40、r flattening and rolling, the silver is extracted (parted) in nitric acid and the gold weighed. Possible systematic errors in the procedure are eliminated by assaying standard proof samples in parallel.NOTE Inquartation is the addition of silver to gold alloys in a specific ratio in order to enable

41、the parting of gold from silver by means of nitric acid.4 ReagentsDuring the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity.4.1 Nitric acid (HNO3), 33 % (mass fraction), with sufficiently low content of halid

42、es (check with silver nitrate test).4.2 Nitric acid (HNO3), 49 % (mass fraction), with sufficiently low content of halides (check with silver nitrate test).4.3 Lead, assay grade, free of precious metals and bismuth, as foil, beads, or tablets.4.4 Pure silver, for inquartation, minimum purity 999 par

43、ts per thousand () by mass, free of gold and platinum group metals.4.5 Pure gold, for proof samplesEN ISO 11426:2016 (E) DIN EN ISO 11426:2016-12 6 for determination of gold between 333 and 990 parts per thousand () by mass, minimum purity 999,9 parts per thousand () by mass, and for determination o

44、f gold more than 990 parts per thousand () by mass, minimum purity 999,99 parts per thousand () by mass.4.6 Pure palladium, for proof samples, minimum purity 999,5 parts per thousand () by mass, free of gold.4.7 Nickel, for proof samples, in a form of an appropriate pre-alloy (free of precious metal

45、s).4.8 Copper (foil or wire), for proof samples, minimum purity 999 parts per thousand () by mass, free of gold and platinum group metals.4.9 Sodiumtetraborate (Na2B4O7), anhydrous.5 Apparatus5.1 Ordinary laboratory apparatus.5.2 Cupellation furnace, in which an oxidizing atmosphere can be maintaine

46、d.CAUTION A standard muffle furnace is not satisfactory for this purpose.5.3 Magnesia cupels, in form of single or block cupels, capable of absorbing the resulting lead and base metal oxides.5.4 Parting flasks or nitric acid resistant basket, with thimbles.5.5 Annealing crucibles, made of refractory

47、 materials.5.6 Cupellation tongs.5.7 Assay pliers.5.8 Polished anvil, which may be replaced by a press, polished and reserved for this purpose.5.9 Polished hammer, of minimum mass 400 g, which may be replaced by a press, polished, and reserved for this purpose.5.10 Scorification dishes, usually of 5

48、0 mm in diameter.5.11 Jewellers rolls.5.12 Scorification tongs.5.13 Assay cleaning brush.5.14 Analytical balance, with a reading accuracy of 0,01 mg.EN ISO 11426:2016 (E) DIN EN ISO 11426:2016-12 7 6 SamplingThe sampling procedure for jewellery gold alloys shall be performed in accordance with ISO 11596.7 ProcedureWARNING Suitable health and safety