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1、INTERNATIONAL STANDARD ISO 6644 Second edition 2002-12-01 Reference number ISO 6644:2002(E) ISO 2002 Flowing cereals and milled cereal products Automatic sampling by mechanical means Crales et produits de mouture des crales en mouvement chantillonnage automatique par des moyens mcaniques Copyright I
2、nternational Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 08:40:02 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6644:2002(E) ii ISO 2002 All rights reserved PDF discl
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7、he 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.ch Web www.iso.ch Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Stand
8、ards 1/9972545001 Not for Resale, 04/22/2007 08:40:02 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6644:2002(E) ISO 2002 All rights reserved iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (
9、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 the right to be represented on that committee. International organizations, go
10、vernmental 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. International Standards are drafted in accordance with the rules given in the ISO/IE
11、C Directives, Part 3. Draft International 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
12、the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 6644 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, Cereals and pulses. This
13、second edition cancels and replaces the first edition (ISO 6644:1981), which has been technically revised. Annex A of this International Standard is for information only. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards
14、 1/9972545001 Not for Resale, 04/22/2007 08:40:02 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6644:2002(E) iv ISO 2002 All rights reserved Introduction Correct sampling is an operation that requires most careful attention. Therefore emphasis cannot be too strongly l
15、aid on the necessity of obtaining a properly representative sample of cereal grain or milled product. Careless or inaccurate sampling could lead to misunderstanding and to unwarranted financial adjustment. The procedures given in this International Standard are recognized as good practice and it is
16、strongly recommended that they be followed whenever practicable. It is difficult to lay down fixed rules to be followed in every case, and particular circumstances may render some modification of the method desirable. For example, determination of qualitative factors, such as moisture content, is be
17、st achieved by examination of the laboratory sample, whereas a quantitative factor, such as detection of insects, is best achieved by examination of individual increments. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standard
18、s 1/9972545001 Not for Resale, 04/22/2007 08:40:02 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARDISO 6644:2002(E) ISO 2002 All rights reserved 1 Flowing cereals and milled cereal products Automatic sampling by mechanical means 1Scope This Internation
19、al Standard specifies requirements for the automatic sampling, by mechanical means, of cereals (as grain) or of milled cereal products moving in bulk, for assessment of their quality. It is not applicable to commodities in sacks or in packages, to static bulks in wagons, ships, bulk tankers, silos o
20、r warehouses1). It does not apply to seed grain. 2Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, this publication do
21、 not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Membe
22、rs of ISO and IEC maintain registers of currently valid International Standards. ISO 13690, Cereals, pulses and milled products Sampling of static batches 3Terms and definitions For the purposes of this International Standard, the following terms and definitions apply. 3.1 consignment quantity of pr
23、oduct dispatched or received at one time and covered by a particular contract or shipping document NOTEIt may be composed of one or more lots. 3.2 lot stated portion of a consignment NOTEUnless otherwise specified in the contract, consignments should be considered in lots of up to 500 tonnes. 3.3 in
24、crement small quantity taken from the product stream during a stated short period of time 3.4 bulk sample quantity of product obtained by combining and mixing thoroughly the increments taken from a specific lot, or obtained from a continuously taken sample allowed to accumulate NOTEFor recommendatio
25、ns on achieving a homogenous mix of large quantities of sampled product, see ISO 13690. 1)For sampling of cereals as grain, see ISO 13690. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04
26、/22/2007 08:40:02 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6644:2002(E) 2 ISO 2002 All rights reserved 3.5 laboratory sample quantity of product divided according to instructions given in ISO 13690 and removed from the bulk sample, and intended for analysis or ot
27、her examination 3.6 flowing product product to be sampled moving through a conveying system, or in free-fall from a spout or chute 4General requirements 4.1Arrangements for fixed or temporary automatic sampling shall be made jointly by the interested parties. 4.2The purpose of sampling is to obtain
28、a sample corresponding in characteristics and composition with the lot from which it was taken. Therefore, the mechanical sampling device, having been installed, suitably adjusted and set in operation, shall automatically take an increment or a series of increments from a lot. Such increment or incr
29、ements may be taken continuously, or intermittently and repeatedly, depending on the device used. 4.3It is normal practice that a product which is sea-damaged or suspected of being contaminated, damaged or out of condition is kept separate from the sound product and is sampled separately. Samples of
30、 the unsound material shall not be mixed with samples of the sound material. 4.4Special care is necessary to ensure that all parts of the sampler are clean, dry and free from foreign odours. 4.5Sampling shall be carried out in such a manner as to protect the samples, the sampler, and the containers
31、in which the samples are placed, from contamination such as rain or dust. In the case of products for human consumption, the installation shall comply with relevant food safety legislation. 5Requirements for apparatus 5.1General Mechanical sampling equipment shall be capable of taking increments fro
32、m the entire cross section, or as much of the cross section as possible, of the flowing bulk material. Annex A gives descriptions of the general types of automatic sampling devices and illustrations of examples of such types. 5.2Adjustment The equipment shall be capable of adjustment such that the s
33、ize of increments and frequency at which they are taken can be varied over the desired wide ranges. 5.3Access Each sampler shall be provided with suitable access for convenient inspection, cleaning, maintenance and repair of all wearing surfaces, and for sampling verification. Access equipment shoul
34、d be constructed of materials that will not generate an electrostatic charge. 5.4Safety The installation shall comply with all applicable safety requirements, including adequate illumination for inspection, operation and maintenance. When used in a potentially dusty environment, the operator should
35、wear a suitable respirator. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 08:40:02 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6644:2002(E) IS
36、O 2002 All rights reserved 3 5.5Location 5.5.1In general it is advisable to take samples from a point as close as possible to the place where the commodity being sampled changes ownership (e.g. just before the loading of a wagon or vessel). 5.5.2Products moving in bulk may be sampled, for example, w
37、hen moving on a conveyor belt, or in an inclined conduit, or when moving in air streams as in a pneumatic lift or conveyor, or when falling from a spout or the end of a conveyor belt. 5.5.3When sampling grain from a spout, it is important that the velocity of the stream does not cause breakage of th
38、e grains. Therefore the apparatus shall be installed not more than from the weighing machine, bin, head of bucket elevator, or discharge point of a pneumatic elevator cyclone. The slope of the spout shall be not less than from horizontal to avoid separation of smaller/lighter fractions from larger/h
39、eavier elements within the stream. 5.5.4When sampling grain from a conveyor belt, the apparatus shall be installed at least from the nearest feeder, turn-head or place where the grain is fed onto the conveyor belt or band, to allow the grain stream elements to achieve near equilibrium a maximum dist
40、ance of . 6Requirements for taking increments 6.1General The increments shall be taken from as wide a cross section of the flowing product as possible, in such a way that almost every part of the lot has an equal opportunity of entering the inlet of the sampler. Some samplers allow full cross-sectio
41、nal sampling; other designs cover to to of the cross section of the product flow. 6.2Continuous sampling A small constant proportion of the lot shall be taken during the period that the lot is flowing past the sampling point. 6.3Intermittent automatic sampling A series of increments of fixed size sh
42、all be taken at predetermined intervals of time. As the characteristics and composition of a lot can vary, the increment or series of increments shall be taken during the whole time that the lot is flowing past the sampling point. 7Bulk samples 7.1A continuously taken sample may be allowed to accumu
43、late to form a bulk sample, during the entire time of sampling a particular lot. If desired, the sample may be divided, intermittently, into increments so that each increment represents a given proportion of the lot flowing past the sampling point during a known time interval. Any bulk sample should
44、 always be thoroughly mixed to ensure the composition is as homogeneous as possible. 7.2A series of intermittently taken samples may be retained as separate increments so that the fluctuations in characteristics and composition of the lot can be assessed. Alternatively, they may be blended together
45、and well mixed to provide a bulk sample. Separate-increment samples may also be retained as laboratory samples if the sample size coincides with requirements. 8Laboratory samples The bulk sample shall be divided into the required number of laboratory samples of the required size by using one or more
46、 of the techniques described in ISO 13690. 4 m 35 2 m 15 m 90 %95 % Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 08:40:02 MDTNo reproduction or networking permitted without li
47、cense from IHS -,-,- ISO 6644:2002(E) 4 ISO 2002 All rights reserved 9Size of samples The automatic sampler should be adjusted so that the sizes of samples given in Table 1 are obtained. These sample sizes are for guidance only, and are not intended to over-ride national requirements or specificatio
48、ns. Larger or smaller laboratory samples may be required in some cases, according the tests to be carried out. 10Packaging and labelling of samples 10.1Packaging of samples 10.1.1The laboratory samples shall be packed in containers suitable for the purpose, bearing in mind the tests to be undertaken. 10.1.2Samples for the determination of moisture, or for other tests in which it is important to avoid the loss of volatile mater (e.g. examination for evidence of chemical treatment), shall be packed in air-tight and vapour-tight containers