1、Designation: D 4872 99 (Reapproved 2004)e1An American National StandardStandard Test Method forDielectric Testing of Wire and Cable Filling Compounds1This standard is issued under the fixed designation D 4872; the number immediately following the designation indicates the year oforiginal adoption or
2、 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.e1NOTENon-mandatory language was replaced throughout editorially in November 2004.1. Scope
3、1.1 This test method covers the determination of dissipationfactor, permittivity (dielectric constant) and ac volume resis-tivity of wire and cable filling compounds and related materialsthat are solid at room temperature, but capable of being meltedat elevated temperature.1.2 This standard does not
4、 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 applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in S
5、ection 7.1.3 Whenever two sets of values are presented, in differentunits, the values in the first set are the standard, while those inparentheses are for information only.2. Referenced Documents2.1 ASTM Standards:2D 150 Test Methods for A-C Loss Characteristics andPermittivity (Dielectric Constant)
6、 of Solid Electrical Insu-lating MaterialsD 257 Test Methods for D-C Resistance or Conductance ofInsulating MaterialsD 1321 Test Method for Needle Penetration of PetroleumWaxesD 1711 Terminology Relating to Electrical InsulationD 6054 Practice for Conditioning Electrical Insulating Ma-terials for Te
7、sting3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 1711.4. Summary of Test Method4.1 Place a measured volume of melted sample, free ofentrapped air, into a level preheated specimen dish. Allow thespecimen to cool and place primary and secondary
8、 electrodesin uniform contact with the specimen surface. Connect testleads to the specimen dish and the cover plate electrode; makemeasurements to obtain values from which dissipation factor,permittivity, and dc volume resistivity are calculated.5. Significance and Use5.1 Dissipation factor, permitt
9、ivity and dc volume resistivityare properties of communication cable fillers and filler com-ponents that are controlled in order that the cables electricalperformance falls within its design limits. Relatively smallamounts of contaminants, such as polar compounds, water orsalts, degrade the cables e
10、lectrical properties. Limits on thedielectric properties of the cable filling compound are usuallyspecified by the cable manufacturer, by industry standards orboth.6. Apparatus6.1 Specimen Dish and Cover Electrode, as shown in Fig. 1.Use a gold- or nickel-plated specimen dish and cover electrodeplat
11、e to ensure a corrosion resistant, high conductivity surface.6.1.1 Clean the specimen dish and electrode plate of oxida-tion by rinsing in a 5 % hydrochloric acid solution for amaximum of 5 s, followed by distilled water, isopropyl alcoholand, finally, by a low boiling petroleum distillate (naphtha)
12、 (seeSection 7). Alternatively, use an ultrasonic cleansing bath.Store the dish and cover, wrapped in paper towels, in adesiccator or in an oven maintained at 50 C.6.2 Dial Comparator, having a minimum travel of 0.4 in.(10.2 mm) or equivalent.6.3 Leveling Table, adjustable to 6 1 min of arc. The bas
13、efrom a Test Method D 1321 penetrometer is satisfactory.6.4 Glass Syringe, 10.0-mL capacity.6.5 Oven, capable of maintaining the temperature used todetermine viscosity for the particular compound under test.6.6 Q-Meter, or equivalent.6.7 Teraohm Meter, or equivalent.1This test method is under the ju
14、risdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.18 on Solid Insulations, Non-Metallic Shieldings, and Cover-ings for Electrical and Telecommunications Wires and Cables.Current edition approved April 10, 1999. Publi
15、shed June 1999. Originallyapproved in 1988. Last previous edition approved in 1994 as D 4872 94.2For referenced ASTM standards, 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 Docume
16、nt Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Hazards7.1 The chemicals used in cleaning the sample dish areconsidered hazardous. Exercise care in handling hydrochloricacid and naphtha. Naphtha
17、is extremely flammable; do not usein an area near sparks or open flame.8. Sample and Test Specimen8.1 The sample is to be representative of the material to betested. Approximately 100 g of material is sufficient for severalspecimens.9. Calibration and Standardization9.1 Follow the calibration and st
18、andardization proceduresfound in the operating manuals for the cited measuringequipment.10. Conditioning10.1 Condition the sample in an atmosphere of 23 6 3Cand 50 6 5 % relative humidity in accordance with PracticeD 6054.11. Procedure11.1 Heat the sample, specimen dish, and syringe for 1.5 60.5 h i
19、n an oven set at a temperature previously determined toproduce a homogeneous liquid.11.2 Remove the sample from the oven and stir gently toensure uniformity, being careful to avoid entraining airbubbles.11.3 Place the specimen dish on the leveled leveling table.With the hot syringe, transfer 5.0 mL
20、of the sample to thespecimen dish in a manner that avoids air bubble entrapment(discharge syringe at or below the specimen surface). Cool thespecimen and specimen dish at 1/23/50 as defined in PracticeD 6054, except the tolerance for temperature shall be 6 3 C.11.4 Gently center the cover electrode
21、on the solidifiedspecimen. The cover electrode should contact the surface of thespecimen.11.5 Transfer the dish with specimen to the comparator.Measure the thickness of the dish base plus the specimen plusthe electrodes to the nearest 0.001 in. (0.0024 mm) in 45increments 0.5 in. (12.7 mm) from the
22、periphery of theelectrode plate. If the greatest difference between the largestand smallest readings is 0.003 in. (0.076 mm) or less, thespecimen is satisfactory. Proceed with the electrical measure-ments. If the difference is greater than 0.003 in., the specimenis excessively wedge-shaped and canno
23、t be used. Prepare anew specimen.11.6 Position the specimen dish (which becomes the baseelectrode) for the dielectric tests.11.7 Determine the dissipation factor and permittivity (di-electric constant) at 1 MHz in accordance with the proceduresfound in the operating manuals for the test equipment be
24、ingused and the calculations found in Test Methods D 150.11.8 Determine the volume resistivity in accordance withthe procedures found in the operating manuals for the testequipment being used and the calculations found in TestMethods D 257.12. Report12.1 Report the following information:12.1.1 Descr
25、iption of the material tested, that is, the name,grade, color, manufacturer, and other pertinent data,12.1.2 Individual thickness measurements and their aver-ages,12.1.3 Conditioning of the specimen, and test conditions,12.1.4 Method of measurement and measurement circuits,12.1.5 Measured values, an
26、d12.1.6 Calculated values of dissipation factor, permittivityand volume resistivity.13. Precision and Bias13.1 PrecisionThe precision of this test method has notbeen determined and no work is planned.13.2 BiasA statement of bias is not possible due to a lackof a standard reference material.14. Keywo
27、rds14.1 cable; dielectric testing; dissipation factor; filling com-pounds; permittivity; volume resistivity; wireFIG. 1 Electrode Plate and Specimen Dish for Dielectric Testingof Wire and Cable Filling CompoundsD 4872 99 (2004)e12ASTM International takes no position respecting the validity of any pa
28、tent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that 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 revisio
29、n at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your com
30、ments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel 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 copyright
31、ed 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).D 4872 99 (2004)e13
