1、INTERNATIONAL STANDARD ISO 11596 First edition 2008-08-15 Reference number ISO 11596:2008(E) ISO 2008 Jewellery Sampling of precious metal alloys for and in jewellery and associated products Joaillerie, bijouterie chantillonnage des alliages de mtaux prcieux pour la joaillerie, bijouterie et produit
2、s associsISO 11596:2008(E) ii ISO 2008 All rights reserved PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the
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6、ermission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in SwitzerlandISO 11596:2008(E) ISO 200
7、8 All rights reserved iii Contents Page 1 Scope 1 2 Terms and definitions 1 3 Tools 3 4 Sample selection . 4 5 Surface preparation before sampling 4 6 Sampling methods . 4 7 Retention of samples 5 Annex A (informative) Guidelines for third-party testing for the usual technique of sample selection 7
8、Bibliography . 9ISO 11596:2008(E) iv ISO 2008 All rights reserved 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
9、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 non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with
10、the International Electrotechnical Commission (IEC) 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 Interna
11、tional Standards adopted by the technical committees 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 b
12、e the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 11596 was prepared by Technical Committee ISO/TC 174, Jewellery.INTERNATIONAL STANDARD ISO 11596:2008(E) ISO 2008 All rights reserved 1 Jewellery Sampling of precious metal alloys for
13、 and in jewellery and associated products 1S c o p e This International Standard specifies a method of sampling precious metal jewellery alloys for the determination of the precious metal content. It is applicable to raw materials, semi-finished products and finished products of the jewellery alloys
14、 of precious metals. The purpose of this International Standard is to define all the operations needed to obtain samples intended for the determination of the precious metal content of a particular jewellery alloy. It is intended to be applied when sampling alloys are claimed to be homogeneous. This
15、 International Standard does not cover alloys of precious metals used in industrial products, coins qualified as legal tender, dentistry or decorative coatings on other material. It is not intended to apply to procedures employed for the purposes of production control or for the provision of samples
16、 other than for the determination of the precious metal content. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 casting process in which a molten alloy is allowed to solidify in a mould NOTE The product obtained by such a process is also ref
17、erred to as a casting. 2.2 casting grain material in discrete droplet or granular form, only suitable for re-melting 2.3 component parts findings products in a form that constitutes components of a finished article 2.4 electroform article produced by an electrolytic process using a metallic or non-m
18、etallic substrate, in which the precious metal coating is sufficiently thick for the article to be used once the substrate is removed NOTE Electroforms from alloys are often not homogeneous. 2.5 hollow tube method method by which a tube of precious metal alloy is manufactured using mechanical means
19、on a non-precious metal support that is removed at the end of the manufacturing process 2.6 ingot cast unwrought product suitable for further manufactureISO 11596:2008(E) 2 ISO 2008 All rights reserved 2.7 jewellery products made of precious metal or precious metal alloys NOTE These products are gen
20、erally intended for ornamentation. 2.8 lot batch product, or collection of units of product, from which a sample (or samples) is (are) to be drawn NOTE Each lot or batch consists of units of product of a single type, grade, class, size and composition, manufactured under essentially the same conditi
21、ons and visibly presenting the same characteristics. 2.9 lot size batch size weight of products, or number of units of product, in a lot or batch 2.10 mixed precious metal jewellery articles made from two or more separate precious metals, or precious metal alloys 2.11 precious metal gold, platinum,
22、palladium or silver 2.12 precious metal alloy material used to form a product with an intended combination of one or more precious metals, usually with one or more other materials, in a homogeneous form 2.13 rod solid wrought product of uniform cross-section along its own length, supplied in straigh
23、t form in defined lengths 2.14 sample quantity of representative material taken from a product, or part of a product 2.15 sampling defined procedure whereby a part of a substance, material or product is taken to provide a representative sample, or samples, of the whole for analysis 2.16 semi-finishe
24、d product product that can be easily used to produce a finished item and/or a component part 2.17 sheet strip flat wrought product of exact length and of rectangular cross-section and uniform thickness NOTE The term “foil” is also sometimes applied to thin sheet. 2.18 solder alloy used to join metal
25、 partsISO 11596:2008(E) ISO 2008 All rights reserved 3 2.19 test portion part of the sample used for the determination of the precious metal content 2.20 tube hollow wrought or cast product of uniform cross-section, with only one enclosed void along its whole length and with uniform wall thickness s
26、upplied in straight lengths or in coiled form 2.21 wire solid wrought product of uniform cross-section along its own length, supplied in coil form, on spools or reels, or as individual lengths 2.22 wrought product product obtained by hot and/or cold plastic deformation processes, such as extruding,
27、forging, hot rolling, cold rolling or drawing, either exclusively or in combination 3 Tools 3.1 General The following list of tools shall be used, which satisfy the criterion of not contaminating the sample: a) power drill mounted in a drilling stand and capable of operating in the range to ; the st
28、and shall have facilities for holding the material being sampled; b) high speed twist drill bits, one for each type of alloy; c) small bench cutter; d) anvil with hard polished face; e) anvil hammer with a convex face and a suitable mass; f) fine-grained grinding paper for cleaning the anvil and ham
29、mer after each use; g) assay shears; h) sample splitters in polished stainless steel; i) fine ( to ) bore quartz or graphite tube with appropriate suction device to extract molten alloy; j) quartz, graphite or carbon-coated stainless steel ladle with a dip capacity of to ; NOTE Carbon coating can be
30、 achieved using a carbon-rich flame. k) shallow open mould in material suitable for rapid cooling without contamination; l) polished laboratory rolling mill; m) saw; n) file; o) scraper consisting of a triangular steel or ceramic rod set in a handle. The above list of tools shall not be considered e
31、xclusive: other tools that satisfy this criterion may also be used. 3.2 Use of tools The relative softness of many of these alloys makes it easy for impurities to become embedded in the sample. Therefore, if sampling involves cutting, the tool used shall be sharp and care shall be taken to ensure th
32、at samples contain representative proportions of the material being sampled. 800 r/min 1 200 r/min 3mm 5mm 5ml 10 mlISO 11596:2008(E) 4 ISO 2008 All rights reserved All tools, machinery and containers used to provide, store, or transport the samples shall be cleaned before use to prevent any contami
33、nation of the sample for analysis. 4 Sample selection The samples shall be selected in accordance with applicable technical standards or recommendations. 5 Surface preparation before sampling Dust, oil, grease, etc. shall be removed by a cleaning agent that leaves no residue on drying. Excess cleani
34、ng agent shall be removed before sampling. Chlorinated hydrocarbons or other harmful substances shall not be used. Any kind of coating shall be removed by an appropriate method (e.g. chemical, mechanical) and any contamination of the precious metal alloy shall be avoided. 6 Sampling methods 6.1 Gene
35、ral The sampling operation shall be carried out in such a way as to produce material capable of acceptable subdivision into equivalent portions. NOTE 1 Annex A provides guidelines for certain products. Where products contain more than one alloy composition of a precious metal, cross-contamination sh
36、all be avoided. For products that have been assembled by soldering, the solder line shall be avoided. NOTE 2 Inclusion of solder in the sample is subject to individual national legislation. 6.2 Dip sampling of molten alloy 6.2.1 Samples shall be taken from well-stirred melts using either of the meth
37、ods described below. When the melt is protected by a non-metallic layer, this should be excluded from the melt sample, or physically separated from the solidified alloy before selecting the test portions. 6.2.2 Method 1 A to diameter quartz or graphite tube shall be used to extract a long cylinder o
38、f molten metal. After removal of all the quartz, the cylinder of metal shall be flattened to provide a thin strip of alloy from which duplicate test portions shall be cut after discarding the first of the two end sections. The required thickness of the strip shall be determined by the rate of attack
39、 by acid in the dissolution process. 6.2.3 Method 2 A ladle made of graphite or carbon-coated steel (for gold and silver) or of quartz (for platinum and palladium), capable of holding about , shall be dipped. The liquid sample shall be cooled rapidly either by a) pouring into water, or b) casting in
40、 a flat mould. This mould shall not be made of a graphite product when casting platinum or palladium. The granules obtained by quenching in water shall be flattened and heated at to until dry, and then subdivided by standard techniques (see Clause A.2) to provide the test sample. 3mm 5mm 7cm 2mm 5ml
41、 150 C 200 CISO 11596:2008(E) ISO 2008 All rights reserved 5 6.2.4 The potential for segregation on cooling and for losses before and during solidification should be assessed before accepting such samples as representatives of the solid form. NOTE When sampling by this technique, precautions are nee
42、ded to prevent the uptake of oxygen. 6.3 Drilling A to twist drill bit shall be operated at about without lubricants, and at least half the thickness of the product shall be drilled. Drillings shall be broken, if necessary, and the broken spiral drillings combined with other material from the same h
43、ole before selecting the test portions for 6 (or 4 or 2) assays. Material from different holes shall not be combined unless it has a mass of less than of the specified mass for the standard methods of analysis. The drills used for this process shall be thoroughly cleaned before use with separate dri
44、lls for each fineness of alloy. Drill bits shall be replaced as necessary. 6.4 Scraping If a scraper is used, it shall be maintained sharp and used by experienced hands, so that it is possible to take samples that are sufficiently uniform and representative without damaging the product. This method
45、shall not be used for electroforms, for any product having a precious metal coating of the substrate or for products obtained using the hollow tube method. 6.5 Cutting When sampling by cutting, a complete cross-section shall be taken. 6.6 Sawing or filing A representative area of the cross-section s
46、hall be sectioned to produce representative samples. Cleaned saws and files shall be used, and the resultant sawings or filings shall be checked for contamination. Contamination from previous use of the saw or file shall be eliminated by discarding the sawings or filings from the initial strokes. Wh
47、en finely divided samples are produced by these processes for analysis by cupellation, spurious results may arise due to spattering. 7 Retention of samples 7.1 General If there is a requirement for retention of samples, proper documented storage shall be carried out. Sample containers shall be label
48、led to provide full identification, and shall be clean and secured in order to avoid contamination or loss. 7.2 Bars, ingots, sheet, rod, tube, wire, casting grain and other raw materials The prepared sample shall weigh at least three times the amount required for an assay in duplicate, where practi
49、cal. 3mm 6mm 1 000 r/min 50 %ISO 11596:2008(E) 6 ISO 2008 All rights reserved 7.3 Component parts and finished products The prepared sample shall provide sufficient material for one assay in duplicate.ISO 11596:2008(E) ISO 2008 All rights reserved 7 Annex A (informative) Guidelines for third-party testing for the usual technique of sample selection A.1 Raw material A.1.1 Cast ingot form and cast bars Each ingot or bar shall be sampled separately, by drilling to a pre-arranged pattern with equal numbers of drillings on the top
