1、April 2013 Translation by DIN-Sprachendienst.English price group 8No 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 5
2、3.040.20!$|H“1988937www.din.deDDIN EN ISO 284Conveyor belts Electrical conductivity Specification and test method (ISO 284:2012);English version EN ISO 284:2012,English translation of DIN EN ISO 284:2013-04Frdergurte Elektrische Leitfhigkeit Spezifikation und Prfverfahren (ISO 284:2012);Englische Fa
3、ssung EN ISO 284:2012,Englische bersetzung von DIN EN ISO 284:2013-04Courroies transporteuses Conductibilit lectrique Spcification et mthode dessai (ISO 284:2012);Version anglaise EN ISO 284:2012,Traduction anglaise de DIN EN ISO 284:2013-04SupersedesDIN EN ISO 284:2004-04www.beuth.deIn case of doub
4、t, the German-language original shall be considered authoritative.Document comprises 11 pages03.13 DIN EN ISO 284:2013-04 2 A comma is used as the decimal marker. National foreword This document (EN ISO 284:2012) has been prepared by Technical Committee ISO/TC 41 “Pulleys and belts (including veebel
5、ts)” (Secretariat: SAC, China), SC 3 “Conveyor belts” (Secretariat: SAC, China and JISC, Japan) and has been taken over as EN ISO 284:2012 by Technical Committee CEN/TC 188 “Conveyor belts” (Secretariat: SNV, Switzerland). The responsible German body involved in its preparation was the Normenausschu
6、ss Kautschuktechnik (Rubber Technology Standards Committee), Working Committee NA 045-02-05 AA Frdergurte. Amendments This standard differs from DIN EN ISO 284:2004-04 as follows: a) the standard has been editorially revised. Previous editions DIN 22104: 1969-12, 1977-05, 1989-10 DIN EN 20284: 1993-
7、05 DIN EN ISO 284: 2004-04 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 284 December 2012 ICS 53.040.10 Supersedes EN ISO 284:2003English Version Conveyor belts - Electrical conductivity - Specification and test method (ISO 284:2012) Courroies transporteuses - Conductibilit lectrique - S
8、pcification et mthode dessai (ISO 284:2012) Frdergurte - Elektrische Leitfhigkeit - Spezifikation und Prfverfahren (ISO 284:2012) This European Standard was approved by CEN on 30 November 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions f
9、or giving this European Standard the status of a national standard 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 thr
10、ee official versions (English, French, German). A version in any 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 bo
11、dies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, 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,
12、Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN
13、 national Members. Ref. No. EN ISO 284:2012: EContents Page Foreword . 3 1 Scope . 4 2 Normative references. 4 3 Specification . 4 4 Test method 4 4.1 Principle 4 4.2 Materials and apparatus 4 4.3 Test pieces 5 4.4 Atmosphere for conditioning and testing . 6 4.5 Procedure 6 4.6 Expression of results
14、 . 7 4.7 Test report . 7 Annex A (informative) Variation of electrical resistance with temperature and humidity 8 Bibliography 9 2DIN EN ISO 284:2013-04 EN ISO 284:2012 (E) Foreword This document (EN ISO 284:2012) has been prepared by Technical Committee ISO/TC 41 Pulleys and belts (including veebel
15、ts) in collaboration with Technical Committee CEN/TC 188 “Conveyor belts” the secretariat of which is held by SNV. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2013, and conflicting nation
16、al standards shall be withdrawn at the latest by June 2013. 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 identifying any or all such patent rights. This document supersedes E
17、N ISO 284:2003. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedo
18、nia, 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. Endorsement notice The text of ISO 284:2012 has been approved by CEN as
19、 a EN ISO 284:2012 without any modification. “”3DIN EN ISO 284:2013-04EN ISO 284:2012 (E)1 ScopeThis International Standard specifies the maximum electrical resistance of a conveyor belt and the corresponding test method.The test is intended to ensure that the belt is sufficiently conductive to avoi
20、d the accumulation of electrical static charge which can be developed during service use.This International Standard is not suitable or applicable to light conveyor belts as described in ISO 21183-11, the static electrical properties of which are measured by ISO 211782.2 Normative referencesThe foll
21、owing 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 document (including any amendments) applies.ISO 18573, Conve
22、yor belts Test atmospheres and conditioning periods3 SpecificationThe electrical resistance of the conveyor belt when tested in accordance with the method described in Clause 4 shall not exceed 3 108 (300 M). Lower values may be specified for special applications.4 Test method4.1 PrincipleAn electri
23、c current of specified voltage is passed via electrodes through a suitably prepared test piece taken from the belt.4.2 Materials and apparatus4.2.1 Sheet of insulating material, a little larger than the test piece.4.2.2 Two cylindrical and coaxial brass electrodes, the base of one being circular and
24、 the other annular.The dimensions and masses are given in Figure 1. The bases of these electrodes shall be machined flat and polished. A flexible insulated wire shall be connected to each electrode.4.2.3 Ohmmeter (resistance-measuring instrument), with a range up to 1010 and accurate to 5 %.4.2.4 So
25、urce of direct current, adjustable to 1 000 V, and not permitting a current greater than 10 mA or causing an energy dissipation of more than 1 W in the test piece.The source of current may be either an accumulator or a rectified, stabilized AC-power supply.4DIN EN ISO 284:2013-04 EN ISO 284:2012 (E)
26、 4.2.5 Contact agent (to ensure good contact between electrodes and test piece), having an electrical surface resistivity no higher than 104.A jelly of suitable composition is given in Table 1.Table 1 Suitable composition of contact agentComponent Proportionmass fractionAnhydrous polyethylene glycol
27、 (molecular mass: 600) 800 mg/gWater 200 mg/gPotassium chloride 10 mg/gSoft soap (pharmaceutical quality) 1 mg/gDimensions in millimetresKey1 electrode of minimum mass of 115 g2 electrode of minimum mass of 900 gFigure 1 Electrodes4.3 Test pieces4.3.1 DimensionsThe test piece shall be square and sha
28、ll be cut from the full thickness of the belt. The length of a side shall be 300 mm minimum.4.3.2 NumberOne test piece shall be taken. If the specification requires that two or more test pieces are to be taken but does not specify how they shall be selected, reference may be made to ISO 2823.5DIN EN
29、 ISO 284:2013-04EN ISO 284:2012 (E)4.3.3 Cleaning of test surfacesIf suitable, clean both surfaces of the test piece by rubbing with Fullers earth, (i.e. hydrated magnesium-aluminium silicate), for example, using a clean cloth. After cleaning away all traces of the powder, wipe the surface with a cl
30、ean cloth moistened with distilled water, then dry with a clean cloth.4.4 Atmosphere for conditioning and testingBefore testing, expose the test piece for at least 2 h to one of the standard laboratory atmospheres specified in ISO 18573. Conduct the test in this atmosphere (see Annex A). An atmosphe
31、re of 23 C 2 C and 50 % 5 % relative humidity is preferred.4.5 Procedure4.5.1 Check test room atmosphere.4.5.2 Paint on one of the surfaces of the test piece the contact agent (4.2.5) in the two areas illustrated in Figure 2. Great care shall be taken to ensure the accuracy of the dimensions of the
32、areas, but the symmetry of the centre is not critical. If the test piece surface is flat, this jelly may be painted on the bottom surface of the cleaned electrodes. In the case of textured surfaces, the two areas shown in Figure 2 shall be painted on the test piece. The test shall be carried out imm
33、ediately after painting.NOTE In the case of covers with surface undulations, contact between the electrodes and the test piece can be improved by thin sheets of metal foil of the same dimensions as the brass electrodes, placed on the liquid contact agent and made to follow the form of the surface by
34、 rubbing lightly with the finger. The brass electrodes are then placed on the foil.4.5.3 Place the test piece on the sheet of insulating material, with the test surface upwards.4.5.4 Clean the lower faces of the brass electrodes and place them on the liquid contact agent pattern on the test piece.4.
35、5.5 Take care not to breathe on the test surface, as any condensation of moisture may falsify the result.4.5.6 Connect the outer electrode to the earth or low-voltage terminal of the measuring instrument.4.5.7 Connect the inner electrode to the high-voltage terminal of the measuring instrument.4.5.8
36、 Measure the resistance after applying the voltage for at least 1 min.4.5.9 Repeat the test on the other surface of the test piece.6DIN EN ISO 284:2013-04 EN ISO 284:2012 (E) Dimensions in millimetresKey1 contact agent (4.2.5)Figure 2 Design to be painted on the test piece4.6 Expression of resultsFo
37、r each surface of the belt subjected to test, record the electrical resistance, in ohms.4.7 Test reportThe test report shall include the following information: complete designation of the conveyor belt material and the manufacturing date; reference to this International Standard, i.e. ISO 284:2012;
38、test room temperature and relative humidity; conditioning period; contact agent applied; voltage applied to the electrodes; results of the tests; date of test; any deviations from the standard test.7DIN EN ISO 284:2013-04EN ISO 284:2012 (E)Annex A (informative) Variation of electrical resistance wit
39、h temperature and humidityA.1 GeneralThe materials used for the covers of conveyor belts are, in terms of electrical resistance, sensitive to their temperature-history and their strain-history. This phenomenon arises because of the structural configuration of the conductive particles (e.g. carbon) i
40、n the polymer and the degree of their orientation, which can change, between the manufacturing stage and installation due to the strain-history of the belt.The antistatic properties of the covers of conveyor belts are also influenced by their electrostatic charging characteristics, which are related
41、 to their relative permittivity, a full discussion of which can be found in IEC 602504.A.2 ConformityThe surface electrical resistance of a conveyor belt cover as measured by this method may vary if the temperature in the test laboratory varies during the test and will fall dramatically if the relat
42、ive humidity rises above 50 %. If a test result does not prove conformity with the requirements of this specification, it is advisable for the test to be repeated at the higher limit of temperature and humidity required by the product specification.8DIN EN ISO 284:2013-04 EN ISO 284:2012 (E) Bibliog
43、raphy1 ISO 21183-1, Light conveyor belts Part 1: Principal characteristics and applications2 ISO 21178, Light conveyor belts Determination of electrical resistances3 ISO 282, Conveyor belts Sampling4 IEC 60250, Recommended methods for the determination of the permittivity and dielectric dissipation factor of electrical insulating materials at power, audio and radio frequencies including metre wavelengths9DIN EN ISO 284:2013-04EN ISO 284:2012 (E)
