ASTM D6095-2006 Standard Test Method for Longitudinal Measurement of Volume Resistivity for Extruded Crosslinked and Thermoplastic Semiconducting Conductor and Insulation Shielding.pdf

1、Designation: D 6095 06An American National StandardStandard Test Method forLongitudinal Measurement of Volume Resistivity forExtruded Crosslinked and Thermoplastic SemiconductingConductor and Insulation Shielding Materials1This standard is issued under the fixed designation D 6095; the number immedi

2、ately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This

3、 test method covers the procedure for determiningthe volume resistivity, measured longitudinally, of extrudedcrosslinked and thermoplastic semiconducting, conductor andinsulation shields for wire and cable.1.2 Whenever two sets of values are presented, in differentunits, the values in the first set

4、are the standard, while those inparentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the

5、applica-bility of regulatory limitations prior to use. For a specifichazard statement, see 7.1.1.4 In common practice the conductor shield is often re-ferred to as the strand shield.1.5 Technically, this test method is the measurement of aresistance between two electrodes on a single surface andmodi

6、fying that value using dimensions of the specimen geom-etry to calculate a resistivity. However, the geometry of thespecimen is such as to support the assumption of a current pathprimarily throughout the volume of the material between theelectrodes, thus justifying the use of the term “longitudinalv

7、olume resistivity.” ( See 3.1.2.1 )2. Referenced Documents2.1 ASTM Standards:2D 257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD 1711 Terminology Relating to Electrical InsulationD 4496 Test Method for D-C Resistance or Conductance ofModerately Conductive Materials3. Termino

8、logy3.1 Definitions of Terms Specific to This Standard:3.1.1 semiconducting, adjmoderately conductive, seeTerminology D 1711 and Test Method D 4496.3.1.2 longitudinal volume resistivity, nan electrical resis-tance multiplied by a factor calculated from the geometry of aspecimen volume between electr

9、odes in contact with one, andonly one, surface of the specimen.3.1.2.1 DiscussionIn normal wire and cable usage, thelongitudinal volume resistivity is simply referred to as “volumeresistivity.” This usage is at variance with terminology in TestMethods D 257, Terminology D 1711, and Test MethodD 4496

10、.4. Significance and Use4.1 The electrical behavior of semiconducting extrudedshielding materials is important for a variety of reasons, suchas safety, static charges, and current transmission. This testmethod is useful in predicting the behavior of such semicon-ducting compounds. Also see Test Meth

11、od D 4496.5. Apparatus5.1 See Test Method D 4496 for a description of theapparatus, except the electrode system which is described in7.2.6. Sampling and Test Specimens6.1 Take one 2-ft (600-mm) sample from each lot, or fromeach 25000 ft (7600 m) of completed cable, whichever is less.6.2 The specimen

12、 consists of a 10 in. (250 mm) length ofcable core with all layers external to the semi-conductinginsulation shield removed. Use this specimen to test the1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibilit

13、y ofSubcommittee D09.18 on Solid Insulations, Nonmetallic Shieldings and Coveringsfor Electrical and Telecommunication Wires and Cables.Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1997. Last previous edition approved in 2005 as D 609505.2For referenced ASTM st

14、andards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM In

15、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.insulation shield. To test the conductor shield, bisect thesample longitudinally and remove the conductor. Use only onepiece of the conductor shield as the test specimen.6.3 Condition the specimens in ac

16、cordance with TestMethod D 4496.6.3.1 If the shielding materials are crosslinked, conditionthe cable core (jacket removed) overnight at 50 C to eliminateany acetophenone that may be present. Then proceed with theconditioning in accordance with Test Method D 4496.7. Procedure7.1 WarningThoroughly ins

17、truct all operators as to thecorrect procedures for performing tests safely.7.2 Apply an electrode system consisting of four annularbands of silver paint approximately 0.25 in. (6.5 mm) wide tothe insulation shield. There must be a distance of at least 2 in.(50 mm) of shield between the potential el

18、ectrodes (the twoinner bands) and a distance of 1 in. of shield between thecurrent electrodes (the outer bands) and the potential elec-trodes. See Annex A1 of Test Method D 4496.7.3 For measurement of the conductor shield, bisect thesample longitudinally and remove the conductor. Then, usingonly one

19、 piece of the bisected shield, apply the silver paintelectrode system as described in 7.2 only to the conductorshield.7.4 Condition the specimen for1hattherated operatingtemperature of the cable to ensure thermal equilibrium of thespecimen.7.5 Determine the resistance between the potential elec-trod

20、es of the test specimen using a direct test voltage and ameasuring system meeting the requirements of Test MethodD 4496. Make two measurements, one at 23 6 2C(736 4F) and one at the rated operating temperature of the insulationmaterial. See the procedure and Appendix X1 of Test MethodD 4496 concerni

21、ng the prevention of specimen self-heating.Limiting the power to 100 mW and the test time to 1 min isrecommended.7.6 When a high degree of accuracy is not required, use atwo-electrode method employing any technique that permitsthe resistance to be measured with an accuracy of 65 %. Spacethe electrod

22、es at least 2 in. (50 mm) apart. Make two tests, oneat 23 6 2C(736 4 F) and one at the rated operatingtemperature of the insulation material.8. Calculation8.1 For each shielding material and each temperature, cal-culate the volume resistivity by using the following equations:Insulation Shielding:r52

23、RDb2 db2! /L (1)Conductor Shielding:r5R Da2 da2! /L (2)where:r = volume resistivity, V-cm,R = measured resistance, V,L = distance between potential electrodes, in.,Da= diameter over conductor shielding, in.,da= diameter over conductor, in.,Db= diameter over insulation shielding, in., anddb= diameter

24、 over insulation, in.NOTE 1Even though the dimensions are measured in inches, the valueof the volume resistivity is reported in V-cm. This is because not allconstants and conversion factors are shown in Eq 1 and Eq 2. SeeAppendix X1 for a discussion on the derivation of the formulas.9. Report9.1 Rep

25、ort the following information:9.1.1 Sample conditioning time and temperature,9.1.2 The volume resistivity, V-cm, of the conductor shield-ing material at 23 6 2 C,9.1.3 The volume resistivity, V-cm, of the conductor shield-ing material at the temperature rating of the insulation,9.1.4 The volume resi

26、stivity, V-cm, of the insulation shield-ing material at 23 6 2 C,9.1.5 The volume resistivity, V-cm, of the insulation shield-ing material at the temperature rating of the insulation, and9.1.6 The electrode system used.10. Precision and Bias10.1 PrecisionThis test method has been in use for manyyear

27、s, but no statement for precision has been made and noactivity is planned to develop such a statement.10.2 BiasA statement of bias is not possible due to a lackof a standard reference material.11. Keywords11.1 conductor shield; conductor shielding material; insula-tion shield; insulation shielding m

28、aterial; moderately conduc-tive; semiconducting shielding materials; semiconductingshields; volume resistivity of shielding materialsD6095062APPENDIX(Nonmandatory Information)X1. DERIVATION OF FORMULAS FOR VOLUME RESISTIVITYX1.1 Insulation Shielding Material Fig. X1.1r5R A/L! (X1.1)A 5 pD2! /4pd2! /

29、4 5 p D2 d2! /4 (X1.2)r5Rp D2 d2! /4L (X1.3)where:r = volume resistivity, V-cm,R = measured resistance, V,D = diameter over insulation shielding, in.,d = diameter over insulation, in., andL = distance between potential electrodes, in.X1.1.1 In Eq X1.3, substituting the numerical value for pand conve

30、rting the values in inches to centimetres results in EqX1.4 which is the same as Eq 1 in 8.1 which gives the volumeresistivity in the customary units of V-cm.r52R D2 d2! /L (X1.4)X1.2 Conductor Shielding Material Fig. X1.2r5RA/L! (X1.5)A 5 $ pD2! /4pd2! /4 %/2 5 $ pD2 d2! % /8 (X1.6)r5Rp D2 d2! /8L

31、(X1.7)where:r = volume resistivity, V-cm,R = measured resistance, V,D = diameter over conductor shielding, in.,d = diameter over conductor, in., andL = distance between potential electrodes, in.X1.2.1 In Eq X1.7, substituting the numerical value for pand converting the values in inches to centimetre

32、s results in EqX1.8 which is the same as Eq 2 in 8.1 which gives the volumeresistivity in the customary units of V-cm.r5R D2 d2! /L (X1.8)SUMMARY OF CHANGESCommittee D09 has identified the location of selected changes to this test method since the last issue,D 6095 05, that may impact the use of thi

33、s test method. (Approved April 1, 2006)(1) Revised paragraph 1.5.(2) Revised paragraphs 3.1.2 and 3.1.2.1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised tha

34、t determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reappro

35、ved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you fe

36、el that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. X1.1 Insulation Shield FIG. X1.2 Conductor ShieldD6095063