1、INTERNATIONAL STANDARD ISO 11713 First edition 2000-05-15 Reference number ISO 11713:2000(E) ISO 2000 Carbonaceous materials used in the production of aluminium Cathode blocks and baked anodes Determination of electrical resistivity at ambient temperature Produits carbons utiliss pour la production
2、de laluminium Blocs cathodiques et anodes cuites Dtermination de la rsistivit lectrique la temprature ambianteISO 11713:2000(E) ii ISO 2000 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
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7、ghtiso.ch Web www.iso.ch Printed in SwitzerlandISO 11713:2000(E) ISO 2000 All rights reserved iii 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 ca
8、rried out through ISO technical com- mittees. 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 liai- son with ISO, also take part in the
9、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 Directives, Part 3. Draft International Standards adopted by the technical
10、 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 International Standard may be the subject of patent rig
11、hts. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 11713 was prepared by Technical Committee ISO/TC 47, Chemistry, Subcommittee SC 7, Aluminium oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium
12、in- dustry.INTERNATIONAL STANDARD ISO 11713:2000(E) ISO 2000 All rights reserved 1 Carbonaceous materials used in the production of aluminium Cathode blocks and baked anodes Determination of electrical resistivity at ambient temperature 1 Scope This International Standard specifies a method for the
13、determination of the electrical resistivity of cathode blocks and baked anodes used in the production of aluminium, using samples at ambient temperature. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this I
14、nternational Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative docu
15、ments 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 Standards. ISO 8007-1:1999, Carbonaceous materials used in the production of aluminium Sampling plans and sampli
16、ng from individual units Part 1: Cathode blocks. ISO 8007-2:1999, Carbonaceous materials used in the production of aluminium Sampling plans and sampling from individual units Part 2: Prebaked anodes. 3 Principle A fixed, constant direct current is passed through a sample of given cross-section. The
17、voltage drop between sen- sors is measured and the electrical resistivity is calculated. 4 Apparatus 4.1 Drilling machine, equipped with a diamond-tipped drill. 4.2 Cutter, with a diamond-coated disk. 4.3 Slide calliper, accurate to . 4.4 Ammeter, accurate to . 4.5 Potentiometer,o rdigital voltmeter
18、, class of accuracy IEC . 4.6 Sample clamping device, equipped with a current supply and voltage sensors which may be points or blades with a radius of curvature not less than . For blades the sensors shall be perpendicular to the axis of the sample. 4.7 Oven, capable of being maintained at . 0,5 %
19、0,5 % 0,5 % 200 m (110 5) CISO 11713:2000(E) 2 ISO 2000 All rights reserved 4.8 Apparatus for the determination of electrical resistivity, (see Figure 1) in which the contact surface be- tween the current supply and the sample has a ratio of where is the diameter of the current supply contactor; is
20、the diameter or width of the sample; and the distance of the voltage sensors from the edge of the sample is greater than , and at least ; the distance between the voltage sensors is greater than , and at least ; the contact force of the contactor of the current supply is not less than ; the contact
21、force of the voltage sensors on the specimen is not less than . 5 Sampling Sample the cathode blocks and baked anodes in accordance with ISO 8007-1 and ISO 8007-2. Key 1T e s t s p e c i m e n 2 Current supply contactor 3 Voltage sensors Figure 1 Principle for resistivity measurements d D 2 3 d D 0,
22、5D 30 mm 0,8D 40 mm 50 N 0,5 N F = Force of 50 NISO 11713:2000(E) ISO 2000 All rights reserved 3 6 Procedure 6.1 Preparation of specimens Note the direction of sampling (see ISO 8007-2:1999) and take test samples of cylindrical or cuboid shape with the following minimum dimensions. All dimensions sh
23、all be greater than or equal to three times the maximum particle size of the dry aggregate: diameter of a cylindrical sample: minimum; or square cross-section: minimum; length of the sample: minimum; variation of the cross-section in the measuring zone: max. Dry the sample in the oven (4.7) at for a
24、t least , then leave to cool. 6.2 Determination Clean the current contactor and the voltage sensors to ensure optimum electrical contact. Determine the mean diameter or mean side of the specimen with the slide calliper (4.3) in the vicinity of the voltage sensors on two perpendicular diameters in th
25、e case of a cylinder and on the four sides in case of a cuboid. Determine the distance, , between the points of the voltage sensors to within . Place the test specimen between the current contactors and apply force of so as to ensure optimum distribution of current. Adjust the direct current so as t
26、o obtain a current density which is not greater than . Put the voltage sensors into place. Measure the current and difference in voltage on the four radii of the cylinder or on the four sides of the cuboid by rotating the test specimen . Ensure that the time during which the current passes through t
27、he test is sufficiently short to prevent any detectable change in resistance. 7C a l c u l a t i o n The resistivity of the specimen, , expressed in micro-ohm metres, is given by the equation where is the difference in voltage, in volts, over length ; is the area of the cross-section, in square cent
28、imetres, of the test specimen; is the current intensity, in amperes; is the distance, in centimetres, between the voltage sensors. 30 mm 30 mm 30 mm 100 mm 0,5 % (110 5) C2 h l 0,5 % 50 N 1A=cm 2 90 = U A I l 10 4 Ul A I lISO 11713:2000(E) 4 ISO 2000 All rights reserved Calculate the result to the n
29、earest integer for values greater than and to one decimal place for values less than . 8P r e c i s i o n 8.1 Repeatability, 8.2 Reproducibility, 9 Test report The test report shall contain the following information: a) a complete identification of the test sample; b) a reference to this Internation
30、al Standard, i.e. ISO 11713; c) the results and the units in which they are expressed; d) any unusual features noted during the determination; e) any operations not included in this International Standard or in the International Standards to which reference is made, or regarded as optional. 20 m 20 m r r = 1,2 m R R = 1,5 mISO 11713:2000(E) ICS 71.100.10 Price based on 4 pages ISO 2000 All rights reserved
