1、Designation: B193 02 (Reapproved 2014)Standard Test Method forResistivity of Electrical Conductor Materials1This standard is issued under the fixed designation B193; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method covers the determina
3、tion of the elec-trical resistivity of metallic electrical conductor material. Itprovides for an accuracy of 60.30 % on test specimens havinga resistance of 0.00001 (10 ) or more. Weight resistivityaccuracy may be adversely affected by possible inaccuracies inthe assumed density of the conductor.1.2
4、 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 applica-bility of regulatory limitations prior to use.2. Referenced Docu
5、ments2.1 ASTM Standards:2A111 Specification for Zinc-Coated (Galvanized) “Iron”Telephone and Telegraph Line WireA326 Specification for Zinc-Coated (Galvanized) High Ten-sile Steel Telephone and Telegraph Line Wire (Withdrawn1990)3B9 Specification for Bronze Trolley WireB105 Specification for Hard-Dr
6、awn Copper Alloy Wires forElectric ConductorsB298 Specification for Silver-Coated Soft or Annealed Cop-per WireB355 Specification for Nickel-Coated Soft orAnnealed Cop-per WireB415 Specification for Hard-Drawn Aluminum-Clad SteelWireB566 Specification for Copper-Clad Aluminum WireB800 Specification
7、for 8000 Series Aluminum Alloy Wirefor Electrical PurposesAnnealed and Intermediate Tem-pers2.2 NIST Document:NBS Handbook 100 Copper Wire Tables43. Resistivity3.1 Resistivity (Explanatory Note 1) is the electrical resis-tance of a body of unit length, and unit cross-sectional area orunit weight.3.2
8、 Volume Resistivity is commonly expressed in ohms for atheoretical conductor of unit length and cross-sectional area; ininch-pound units in cmil/ft and in acceptable metric units inmm2/m. It may be calculated by the following equation:v5 A/L!Rwhere:v= volume resistivity, cmil/ft or mm2/m,A = cross-s
9、ectional area, cmil or mm2,L = gage length, used to determine R,ftorm,andR = measured resistance, .3.3 Weight Resistivity is commonly expressed in ohms for atheoretical conductor of unit length and weight. The methodfor calculating weight resistivity, based on resistance, length,and weight measureme
10、nts, of a test specimen is given inExplanatory Note 2.4. Apparatus4.1 Resistance shall be measured with a circuit configura-tion and instrumentation that has a resistance measurementcapability of 60.15 % accuracy.5. Test Specimen5.1 The test specimen may be in the form of a wire, strip,rod, bar, tub
11、e, or shape. It shall be of uniform cross sectionthroughout its length within 60.75 % of the cross-sectionalarea. Wherever possible it shall be the full cross section of thematerial it represents, if the full cross section is such that theuniformity of the cross-sectional area can be accurately dete
12、r-mined.1This test method is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.02 onMethods of Test and Sampling Procedure.Current edition approved April 1, 2014. Published April 2014. Originallyapproved in 1944. Last previous e
13、dition approved in 2008 as B193 02 (2008).DOI: 10.1520/B0193-02R14.2For 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 Document Summary page onthe ASTM we
14、bsite.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
15、 West Conshohocken, PA 19428-2959. United States15.2 The test specimen shall have the following characteris-tics:5.2.1 A resistance of at least 0.00001 (10 ) in the testlength between potential contacts,5.2.2 A test length of at least 1 ft or 300 mm,5.2.3 A diameter, thickness, width, or other dimen
16、sionsuitable to the limitations of the resistance measuringinstrument,5.2.4 No surface cracks or defects visible to the unaidednormal eye, and substantially free from surface oxide, dirt, andgrease, and5.2.5 No joints or splices.6. Procedure6.1 Make all determinations of the dimensions and weightof
17、the test specimen using instruments accurate to 60.05 %. Inorder to assure this accuracy in measuring the length betweenpotential contacts, the surface in contact with the test specimenshall be a substantially sharp knife-edge when using a Kelvin-type bridge or a potentiometer.6.2 The cross-sectiona
18、l dimensions of the specimen may bedetermined by micrometer measurements, and a sufficientnumber of measurements shall be made to obtain the meancross section to within 60.10 %. In case any dimension of thespecimen is less than 0.100 in. and cannot be measured to therequired accuracy, determine the
19、cross-section from the weight,density, and length of the specimen.6.3 When the density is unknown, determine the density byweighing a specimen first in air and then in a liquid of knowndensity at the test temperature, which shall be room tempera-ture to avoid errors due to convection currents. Exerc
20、ise care inremoving all air bubbles from the specimen when weighing itin the liquid. Calculate the density from the following equa-tion: 5 Wa3d!/Wa2 Wl!where: = density of the specimen, g/cm3;Wa= weight of the specimen in air, g;Wl= weight of the specimen in the liquid, g; andd = density of the liqu
21、id at the test temperature, g/cm3.6.4 When potential leads are used, make sure the distancebetween each potential contact and the corresponding currentcontact is at least equal to 112 times the cross-sectionalperimeter of the specimen. Make sure the yoke resistance(between reference standard and tes
22、t specimen) is appreciablysmaller than that of either the reference standard or the testspecimen unless a suitable lead compensation method is used,or it is known that the coil and lead ratios are sufficientlybalanced so that variation in yoke resistance will not decreasethe bridge accuracy below st
23、ated requirements.6.5 Make resistance measurements to an accuracy of60.15 %. To ensure a correct reading, allow the referencestandard and the test specimen to come to the same temperatureas the surrounding medium. (If the reference standard is madeof manganin it is possible to obtain correct reading
24、s with thetest specimen at reference temperatures other than roomtemperature). In all resistance measurements, the measuringcurrent raises the temperature of the medium. Therefore, takecare to keep the magnitude of the current low, and the time ofits use short enough so that the change in resistance
25、 cannot bedetected with the galvanometer. To eliminate errors due tocontact potential, take two readings, one direct and one withcurrent reversed, in direct succession. Check tests are recom-mended whereby the specimen is turned end for end, and thetest repeated. Surface cleaning of the specimen at
26、current andpotential contact points may be necessary to obtain goodelectrical contact.TABLE 1 Resistivity and Conductivity ConversionNOTE 1These factors are applicable only to resistivity and conductivity values corrected to 20C (68F). They are applicable for any temperaturewhen used to convert betw
27、een volume units only or between weight units only. Values of density, , for the common electrical conductor materials, arelisted in Table 2.Given NPerform indicatedoperationto obtain Volume Resistivity at 20C Weight Resistivity at 20C Conductivity at 20Ccmil/ft mm2/m in. cm lb/mile2g/m2% IACS(Volum
28、e Basis)% IACS(Weight Basis)Volume Resistivity at 20Ccmil/ft . . . N 601.52 N 15.279 N 6.0153 N 0.10535 (l /)N 601.53 (l/)(l/N) 1037.1 (l/N) 9220.0(l/)mm2/m N 0.0016624 . . . N 0.025400 N 0.010000 N 0.00017513(1/)N (l/)(l/N) 1.7241 (1/N) 15.328(l/)in. N 0.065450 N 39.370 . . . N 0.39370 N 0.0068950(
29、l/)N 39.370 (l/)(l/N) 67.879 (l/N) 603.45(l/)cm N 0.16624 N 100.00 N 2.5400 . . . N 0.017513 (1/)N 100.00 (l/)(l/N) 172.41 (l/N) 1532.8(l/)Weight Resistivity at 20Clb/mile2N 9.4924 N 5710.0 N 145.03 N 57.100 . N 5710.0 (l/N) 9844.8 (l /N) 87520g/m2N 0.0016624 N N 0.025400 N 0.010000 N 0.00017513 . .
30、 . (l/N) 1.7241 (l/N) 15.328Conductivity at 20C% IACS(volume basis)(1/N) 1037.1 (1/N) 1.7241 (1/N) 67.879 (1/N) 172.41 (1/N) 9844.8 (l /N) 1.7241 . N 0.11249 % IACS(weight basis)(l/N) 9220.0(l/)(1/N) 15.328(l/)(l/N) 603.45(l/)(l/N) 1532.8(l/)(l/N) 87520 (l/N) 15.328 N 8.89 (l /) .B193 02 (2014)2TABL
31、E 2 Density and Temperature Coefficient of Resistance for Electrical Conductor MaterialsMaterialApproximate Density, at 20C, g/cm3TemperatureCoefficient ofResistance, ,at20CMaterialApproximate Density, at 20C, g/cm3TemperatureCoefficient ofResistance, ,at20CCopper, % IACS: Aluminum Alloy 8000,101 8.
32、89 0.00397 Specification B800, % IACS:100 8.89 0.00393 61.8 2.71 0.0040898.40 8.89 0.00387 61.5 2.71 0.0040698.16 8.89 0.00386 61.4 2.71 0.0040697.80 8.89 0.00384 61.3 2.71 0.0040597.66 8.89 0.00384 61.2 2.71 0.0040497.40 8.89 0.00383 61.0 2.71 0.0040397.16 8.89 0.00382 60.9 2.71 0.0040296.66 8.89 0
33、.00380 60.8 2.71 0.0040296.16 8.89 0.00378 60.7 2.71 0.0040194.16 8.89 0.00370 60.6 2.71 0.0040093.15 8.89 0.00366Aluminum Alloy 6101,Silver Coated Copper, % IACS:Specification B298: 59.5 2.70 0.00393Class A 8.91 0.00393 59.0 2.70 0.00390Class B 8.93 0.00393 57.0 2.70 0.00377Class C 8.95 0.00394 56.
34、5 2.70 0.00373Class D 8.99 0.00394 56.0 2.70 0.00370Class E 9.05 0.00395 55.0 2.70 0.0036354.0 2.70 0.00357Nickel Coated Copper, 53.0 2.70 0.00350Specification B355:Class 2 8.89 0.00395 Aluminum Alloy, % IACS:Class 4 8.89 0.00397 5005-H19 53.5 2.70 0.00353Class 7 8.89 0.00400 6201-T81 52.5 2.69 0.00
35、347Class 10 8.89 0.00404Class 27 8.89 0.00422 Aluminum Clad Steel,% IACS:20.3 6.59 0.003627 5.91 0.003630 5.61 0.003840 4.64 0.0040Bronze, Specification B9:Alloy 40 8.89 0.00157 Copper Clad Steel:Alloy 55 8.89 0.00224 Grade 30 A, HS, EHS 8.15 0.00378Alloy 80 8.89 0.00322 Grade 40 A, HS, EHS 8.25 0.0
36、0378Copper Alloy, Specification Galvanized Steel (Telephone andB105: Telegraph), SpecificationGrade 8.5 8.78 0.00042 A111:Grade 13 8.78 0.00063 Class A Coating:Grade 15 8.54 0.00072 Grade EBB (Non cu-brg) 7.83 0.0056Grade 20 8.89 0.00079 Grade BB (Cu-brg) 7.83 0.0046Grade 30 8.89 0.00118 Grade BB (N
37、on cu-brg) 7.83 0.0042Grade 40 8.89 0.00157 Class B Coating:Grade 55 8.89 0.00224 Grade EBB (Non cu-brg) 7.80 0.0056Grade 74 8.89 0.00299 Grade BB (Cu-brg) 7.80 0.0046Grade 80 8.89 0.00322 Grade BB (Non cu-brg) 7.80 0.0042Grade 85 8.89 0.00342 Class C Coating:Grade EBB (Non cu-brg) 7.77 0.0056Alumin
38、um 1350, % IACS: Grade BB (cu-brg) 7.77 0.004661.8 2.705 0.00408 Grade BB (Non cu-brg) 7.77 0.004261.5 2.705 0.0040661.4 2.705 0.00406 Copper Clad Aluminum,61.3 2.705 0.00405 Specification B566:61.2 2.705 0.00404 Class 10A and 10H 3.32 0.0040561.0 2.705 0.00403 Class 15A and 15H 3.63 0.00404Galvaniz
39、ed Steel,Specification A326:Class A Coating:Grade 85 7.83 0.0046Grade 135 and 195 7.83 0.0042Class B Coating:Grade 85 7.80 0.0046Grade 135 and 195 7.80 0.0042Class C Coating:Grade 85 7.77 0.0046Grade 135 and 195 7.77 0.0042B193 02 (2014)37. Temperature Correction7.1 When the measurement is made at a
40、ny other than areference temperature, the resistance may be corrected formoderate temperature differences to what it would be at thereference temperature, as follows:RT5Rt11Tt 2 T!where:RT= resistance at reference temperature T,Rt= resistance as measured at temperature t,T= known or given temperatur
41、e coefficient of resistance ofthe specimen being measured at reference temperatureT,T = reference temperature, andt = temperature at which measurement is made.NOTE 1The parameter T, in the above equation, varies with conduc-tivity and temperature. For copper of 100 % conductivity and a referencetemp
42、erature of 20C, its value is 0.00393. Values at other conductivitiesand temperatures will be found in NBS Handbook 100.4Table 1 liststemperature coefficients for the common electrical conductor materials.8. Report8.1 For referee tests, report the following information:8.1.1 Identification of test sp
43、ecimen,8.1.2 Kind of material,8.1.3 Test temperature,8.1.4 Test length of specimen,8.1.5 Method of obtaining cross-sectional area:8.1.5.1 If by micrometer, the average values of micrometerreadings, or8.1.5.2 If by weighing, a record of length, weight, anydensity determinations that may be made, and
44、calculatedcross-sectional areas.8.1.6 Weight, if used,8.1.7 Method of measuring resistance,8.1.8 Value of resistance,8.1.9 Reference temperature,8.1.10 Calculated value of resistivity at the referencetemperature, and8.1.11 Previous mechanical and thermal treatments. (Sincethe resistivity of a materi
45、al usually depends upon them, theseshall be stated whenever the information is available.)8.2 For routine tests, only such of the items in 8.1 as applyto the particular case, or are significant, shall be reported.9. Precision and Bias9.1 PrecisionThis test method has been in use for manyyears. No st
46、atement of precision has been made and no workhas been planned to develop such a statement.9.2 BiasThis test method has no bias because the value forresistivity is determined solely in terms of this test method.10. Keywords10.1 conductivity; electrical conductor materials; resistivity;resistivity of
47、 electrical conductor; volume resistivity; weightresistivityEXPLANATORY NOTESNOTE 1Volume resistivity is used in place of “weight resistivity” and“percent conductivity.”Resistivity units are based on the International Annealed CopperStandard (IACS) adopted by IEC in 1913, which is 1/58 mm2/m at 20C(
48、68F) for 100 % conductivity. The value of 0.017241 mm2/m and thevalue of 0.15328 g/m2at 20C (68F) are respectively the internationalequivalent of volume and weight resistivity of annealed copper equal (tofive significant figures) to 100 % conductivity. The latter term means thata copper wire1minleng
49、th and weighing 1 g would have a resistance of0.15328 . This is equivalent to a resistivity value of 875.20 lb/mile2,which signifies the resistance of a copper wire 1 mile in length weighing1 lb. It is also equivalent, for example, to 1.7241 /cm of length of acopper bar 1 cm2in cross section. A complete dis
