1、BRITISH STANDARD BS 6043-3.1.2: 1999 ISO 8007-2: 1999 Methods of sampling and test for carbonaceous materials used in aluminium manufacture Part 3: Electrodes Section 3.1: Sampling Subsection 3.1.2: Sampling of anodes ICS 71.100.10BS6043-3.1.2:1999 This British Standard, having been prepared under t
2、he directionof the Sector Committeefor Materials and Chemicals, was published underthe authority of the Standards Committee and comes into effect on 15 October 1999 BSI 04-2000 ISBN 0 580 32815 5 National foreword This British Standard is the UK national implementation of ISO8007-2:1999. The UK part
3、icipation in its preparation was entrusted to Technical Committee CII/24, Raw materials for the aluminium industry, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for
4、 change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international
5、or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all t
6、he necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii
7、, theISO title page, pages ii to iv, pages 1 to 9 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS6043-
8、3.1.2:1999 BSI 04-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 8007-2 1ii blankBS6043-3.1.2:1999 ii BSI 04-2000 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Sampling plans for large consignments or for batches 1 4.1 General 1 4
9、.2 Single unit of product 1 4.3 Drawing up a sampling plan based on acceptable quality level (AQL) 1 4.4 Operating the sampling plan based on acceptable quality level (AQL) 2 4.5 Drawing up a sampling plan based on average test values 5 5 Taking test samples from individual anodes 5 5.1 Procedure 5
10、5.2 Dimensions of test samples 5 5.3 Sampling points 5 6 Sampling report 5 Annex A (informative) Examples 9 Figure 1 Examples of the locations and the direction of sampling fordifferentsizes and designs of anode blocks 6 Table 1 Recommended values for operating the sampling plan 2 Table 2 Sample-siz
11、e code-letter 2 Table 3 Sampling plans for normal inspection (master table) 3 Table 4 Sampling plans for tightened inspection (master table) 4BS6043-3.1.2:1999 BSI 04-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS
12、O 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, gove
13、rnmental 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/IEC
14、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. International Standard ISO 8007-2 was prepared by Tec
15、hnical Committee, ISO/TC 47, Chemistry, Subcommittee SC 7, Aluminium oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium industry. ISO 8007 consists of the following parts, under the general title, Carbonaceous materials used in the production of aluminium S
16、ampling plans and sampling from individual units: Part 1: Cathode blocks; Part 2: Prebaked anodes. Part 3, which is in preparation, will give procedures for sampling sidewall blocks. Annex A of this part of ISO 8007 is for information only.iv blankBS6043-3.1.2:1999 BSI 04-2000 1 1 Scope This part of
17、 ISO 8007 specifies procedures for the creation and execution of a sampling plan for prebaked anodes from a large consignment or from a batch. NOTEThe term “batch” can be substituted by the term “lot” if desired. This part of ISO 8007 also specifies the preferred locations for taking test samples fr
18、om individual anodes. Cathode blocks and prebaked anodes are considered separately. Procedures for sampling cathode blocks are given in ISO 8007-1. For advice on safety, the reader is referred to ISO3165:1976, Sampling of chemical products for industrial use Safety in sampling. 2 Normative reference
19、s The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 8007. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of
20、ISO 8007 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International
21、 Standards. ISO 3534 (all parts), Statistics Vocabulary and symbols. ISO 5022:1979, Shaped refractory products Sampling and acceptance testing. 3 Definitions For the purposes of this part of ISO 8007, the definitions given in ISO3534 (all parts) and ISO5022 apply. 4 Sampling plans for large consignm
22、ents or for batches 4.1 General The sampling plan may be defined in terms of an acceptable quality level (AQL). It may be applied when the parties concerned have agreed to do so and have therefore, by common consent, made a choice between the various options described in this part of ISO 8007. The p
23、arties shall also agree on the various properties to be measured (for example, density and electrical resistivity) so that the sampling plan is suitable for its ultimate purpose of providing representative samples for subsequent testing. It is also possible to apply the procedures given in this part
24、 of ISO 8007 while modifying, by prior agreement between the parties concerned, the recommended values given in the sampling plans (see Table 1, Table 2, Table 3 and Table 4). The efficiency of a sampling plan depends solely on the number of sampled units, n, whatever the size of the batch, N, provi
25、ded that n/N is less than 10 %. Table 1, Table 2, Table 3 and Table 4 shall be used to determine, on the basis of the required efficiency, what the sample size, n, shall be. If experience shows that the quality of the manufacturers production corresponds to the agreements, it is possible, when batch
26、es of the same quality are frequently subjected to acceptance procedures, that a plan with lower efficiency be chosen. This would imply the use of a smaller sample size, n. If later experience shows that the quality of production fails to correspond to the agreements when judged against pre-set crit
27、eria, then it is necessary to return to the original, higher efficiency, sampling plan. Alternatively, a sampling plan may be defined in terms of average test values together with a limitation on the range of test values instead of, or in addition to, acceptable quality levels (AQLs). Statistical pr
28、ocess control (SPC) or statistical quality control (SQC) charts are recommended tools when operating the sampling plan. 4.2 Single unit of product The single unit of product shall be agreed between seller and buyer. It may be a single prebaked anode or it may be 1 t of anodes. 4.3 Drawing up a sampl
29、ing plan based on acceptable quality level (AQL) Before the sampling plan can be drawn up from the tables, it is necessary to agree on the parameters given below: a) The acceptable quality level, i.e. the poorest quality that can be considered acceptable as the process average. b) Whether normal or
30、tightened inspection is to be used. This is decided by studying the sampling results for the last few batches. The rules for switching from one kind of inspection to another are given in 4.5.2. c) The batch size, which may be the amount produced in a production batch (or lot) or, preferably, the amo
31、unt produced or received in a one-month time period.BS6043-3.1.2:1999 2 BSI 04-2000 Table 1 Recommended values for operatingthe sampling plan 4.4 Operating the sampling plan based on acceptable quality level (AQL) 4.4.1 Table 1 gives suitable values for the three parameters described in 4.3. Buyer a
32、nd seller may replace the recommended values with their own values if required. This shall be included in the sampling report see 6 c). 4.4.2 Refer to Table 2 and, using the agreed values from Table 1, find the correct sample-size code-letter (SSCL). Table 2 Sample-size code-letter 4.4.2.1 If the qu
33、ality control or quality assurance plan is being operated by acceptance number (Ac) and rejection number (Re) for the acceptance or rejection of a batch, refer to Table 3 and use the SSCL and AQL values to obtain the acceptance and rejection number. 4.4.2.2 If the sampling plan is being operated on
34、tightened sampling, then refer to Table 4 to get the acceptance number (Ac) and rejection number (Re) values. 4.4.2.3 The acceptability of a batch is determined by testing the samples obtained in accordance with the agreed sampling plan. If the number of defective units, or the tonnage of defective
35、units, found in the sample population is equal to or less than the acceptance number (Ac), then the batch shall be considered acceptable. If the number of defectives is equal to or greater than the rejection number (Re), then the batch shall be rejected as non-conforming. NOTE 1In this case, it is s
36、trongly recommended that the buyer and seller discuss an action plan. The recommended action plan is to divide the original batch or consignment into two or more smaller batches or consignments. Each of these should be sampled in accordance with this part of ISO 8007 and then re-examined. The object
37、ive is to minimize the number of anodes which have to be rejected. NOTE 2It is strongly recommended that it is agreed in advance how the extra expense arising from any re-sampling and re-testing is divided between seller and buyer. An 80 : 20 apportionment may be considered appropriate. The words “d
38、efective unit” shall apply to any unit which gives a value in a contractual-specification test which is outside the agreed range of acceptability. For most purposes, the acceptability range is defined in terms of a maximum value, or a minimum value, or both. Acceptable quality level (AQL) 2,5 Normal
39、 or tightened inspection Normal Batch size Tonnes per month ofproduction or number of units of product in batch or lot Lot or batch size Sample-sizecode-letter (see Table 3 and Table 4) 2 to 8 A 9 to 15 B 16 to 25 B 26 to 50 C 51 to 90 C 91 to 150 D 151 to 280 E 281 to 500 F 501 to 1200 G 1201 to 32
40、00 H 3201 to 10000 J 10001 to 35000 K 35001 to 150000 L 1500001 to 500000 M 500001 and over NBS6043-3.1.2:1999 BSI 04-2000 3 Table 3 Sampling plans for normal inspection (master table)BS6043-3.1.2:1999 4 BSI 04-2000 Table 4 Sampling plans for tightened inspection (master table)BS6043-3.1.2:1999 BSI
41、04-2000 5 4.5 Drawing up a sampling plan based on average test values 4.5.1 If the quality control or quality assurance plan is to be operated on the basis of average test values for a representative sample, then the first two columns of Table 3 give the sample size if normal inspection is to be use
42、d to determine the number of units (anodes) to be sampled. If tightened inspection is to be used, then the first two columns of Table 4 apply. 4.5.2 Switching between normal and tightened inspection shall be carried out as follows: 4.5.2.1 Normal inspection shall be used at the start of inspection u
43、nless otherwise agreed by both parties. 4.5.2.2 When normal inspection is being used, tightened inspection shall be instituted if two out of five consecutive batches have been determined not to be acceptable according to the sampling plan. 4.5.2.3 When tightened inspection is being used, normal insp
44、ection shall be instituted if five consecutive batches have been determined to be acceptable according to the sampling plan. 5 Taking test samples from individual anodes 5.1 Procedure Using suitable core-drilling or sawing equipment with cutting edges preferably coated with diamond or another extrem
45、ely hard material, take test samples in accordance with 5.2 and 5.3. 5.2 Dimensions of test samples Choose the dimensions of each test sample according to the test to be carried out. Refer to the International Standards relating to the tests to be carried out to ensure that the samples taken from th
46、e anode are of suitable dimensions. NOTEIf there are no instructions in the relevant International Standards, then the following guidelines should be followed: a) Samples of circular cross-section are preferred. A sample diameter of 50 mm is recommended. b) The smallest dimension of the sample shoul
47、d be three times the maximum particle size of the dry aggregate. c) The length of the sample should be at least 1,5 times the diameter for samples of circular cross-section and 1,5 times the diagonal if the sample has a square cross-section. The test samples taken from the anode may already be of th
48、e correct dimensions. If not, they shall enable test pieces to be core-drilled or sawn or turned on a lathe from the test sample with a tolerance of0,1mm. The dimensions of the test samples shall be sufficient to allow test pieces with parallel sides to be prepared. Report the dimensions of the test
49、 samples taken and the locations of the sampling points in the sampling report see item 6 d). 5.3 Sampling points Figure 1 shows, in principle, the locations of sampling points and the direction of sampling for different sizes and designs of anode block. The application of the sampling procedure shall not cause, as far as is possible, contamination, weakening or destruction of the anode block. 6 Sampling report The sampling report shall contain the following information: a) the names of the producer and customer; b) identificatio
