1、Designation: B193 02 (Reapproved 2014)B193 16Standard 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 o
2、f last 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 de
3、termination of the electrical resistivity of metallic electrical conductor material. It providesfor an accuracy of 60.30 % on test specimens having a resistance of 0.00001 (10 ) or more. Weight resistivity accuracy maybe adversely affected by possible inaccuracies in the assumed density of the condu
4、ctor.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Reference
5、d Documents2.1 ASTM Standards:2A111 Specification for Zinc-Coated (Galvanized) “Iron” Telephone and Telegraph Line WireA326 Specification for Zinc-Coated (Galvanized) High Tensile Steel Telephone and Telegraph Line Wire (Withdrawn 1990)3B9 Specification for Bronze Trolley WireB105 Specification for
6、Hard-Drawn Copper Alloy Wires for Electric ConductorsB298 Specification for Silver-Coated Soft or Annealed Copper WireB355 Specification for Nickel-Coated Soft or Annealed Copper WireB415 Specification for Hard-Drawn Aluminum-Clad Steel WireB498/B498M Specification for Zinc-Coated (Galvanized) Steel
7、 Core Wire for Use in Overhead Electrical ConductorsB566 Specification for Copper-Clad Aluminum WireB606 Specification for High-Strength Zinc-Coated (Galvanized) Steel Core Wire for Aluminum and Aluminum-AlloyConductors, Steel ReinforcedB800 Specification for 8000 Series Aluminum Alloy Wire for Elec
8、trical PurposesAnnealed and Intermediate TempersB802 Specification for Zinc-5% Aluminum-Mischmetal Alloy-Coated Steel Core Wire for Aluminum Conductors, SteelReinforced (ACSR)Metric(Discontinued 1998-Replaced by B 802/B802M) B0802_B0802MB803 Specification for High-Strength Zinc5 % Aluminum-Mischmeta
9、l Alloy-Coated Steel Core Wire for Use in OverheadElectrical ConductorsB957 Specification for Extra-High-Strength and Ultra-High-Strength Zinc-Coated (Galvanized) Steel Core Wire for OverheadElectrical ConductorsB958 Specification for Extra-High-Strength and Ultra-High-Strength Class A Zinc5% Alumin
10、um-Mischmetal Alloy-CoatedSteel Core Wire for Use in Overhead Electrical Conductors2.2 NIST Document:NBS Handbook 100 Copper Wire Tables43. Resistivity3.1 Resistivity (Explanatory Note 1) is the electrical resistance of a body of unit length, and unit cross-sectional area or unitweight.1 This test m
11、ethod is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.02 on Methods ofTest and Sampling Procedure.Current edition approved April 1, 2014April 1, 2016. Published April 2014April 2016. Originally approved in 1944. Last previ
12、ous edition approved in 20082014 asB193 02 (2008).(2014). DOI: 10.1520/B0193-02R14.10.1520/B0193-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstan
13、dards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.4 Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.This document is no
14、t an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriat
15、e. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2 Volume Resistivity is commonly expressed in ohms for a theoreti
16、cal conductor of unit length and cross-sectional area; ininch-pound units in cmil/ft and in acceptable metric units in mm2/m. It may be calculated by the following equation:v 5A/L!Rwhere:v = volume resistivity, cmil/ft or mm2/m,A = cross-sectional area, cmil or mm2,L = gage length, used to determine
17、 R, ft or m, andR = measured resistance, .3.3 Weight Resistivity is commonly expressed in ohms for a theoretical conductor of unit length and weight. The method forcalculating weight resistivity, based on resistance, length, and weight measurements, of a test specimen is given in ExplanatoryNote 2.4
18、. Apparatus4.1 Resistance shall be measured with a circuit configuration and instrumentation that has a resistance measurement capabilityof 60.15 % accuracy.5. Test Specimen5.1 The test specimen may be in the form of a wire, strip, rod, bar, tube, or shape. It shall be of uniform cross section throu
19、ghoutits length within 60.75 % of the cross-sectional area. Wherever possible it shall be the full cross section of the material itrepresents, if the full cross section is such that the uniformity of the cross-sectional area can be accurately determined.5.2 The test specimen shall have the following
20、 characteristics:5.2.1 A resistance of at least 0.00001 (10 ) in the test length 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 dimension suitable to the limitations of the resistance measuring instrument,5.2.4 No surface cracks
21、 or defects visible to the unaided normal eye, and substantially free from surface oxide, dirt, and grease,and5.2.5 No joints or splices.6. Procedure6.1 Make all determinations of the dimensions and weight of the test specimen using instruments accurate to 60.05 %. In orderto assure this accuracy in
22、 measuring the length between potential contacts, the surface in contact with the test specimen shall bea substantially sharp knife-edge when using a Kelvin-type bridge or a potentiometer.6.2 The cross-sectional dimensions of the specimen may be determined by micrometer measurements, and a sufficien
23、t numberof measurements shall be made to obtain the mean cross section to within 60.10 %. In case any dimension of the specimen is lessthan 0.100 in. and cannot be measured to the required accuracy, determine the cross-section from the weight, density, and lengthof the specimen.6.3 When the density
24、is unknown, determine the density by weighing a specimen first in air and then in a liquid of knowndensity at the test temperature, which shall be room temperature to avoid errors due to convection currents. Exercise care inremoving all air bubbles from the specimen when weighing it in the liquid. C
25、alculate the density from the following equation:5Wa 3d!/Wa 2Wl!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 liquid at the test temperature, g/cm3.6.4 When potential leads are used, make sure the dis
26、tance between each potential contact and the corresponding current contactis at least equal to 112 times the cross-sectional perimeter of the specimen. Make sure the yoke resistance (between referencestandard and test specimen) is appreciably smaller than that of either the reference standard or the
27、 test specimen unless a suitablelead compensation method is used, or it is known that the coil and lead ratios are sufficiently balanced so that variation in yokeresistance will not decrease the bridge accuracy below stated requirements.6.5 Make resistance measurements to an accuracy of 60.15 %. To
28、ensure a correct reading, allow the reference standard andthe test specimen to come to the same temperature as the surrounding medium. (If the reference standard is made of manganin itis possible to obtain correct readings with the test specimen at reference temperatures other than room temperature)
29、. In allresistance measurements, the measuring current raises the temperature of the medium. Therefore, take care to keep the magnitudeof the current low, and the time of its use short enough so that the change in resistance cannot be detected with the galvanometer.B193 162To eliminate errors due to
30、 contact potential, take two readings, one direct and one with current reversed, in direct succession. Checktests are recommended whereby the specimen is turned end for end, and the test repeated. Surface cleaning of the specimen atcurrent and potential contact points may be necessary to obtain good
31、 electrical contact.7. Temperature Correction7.1 When the measurement is made at any other than a reference temperature, the resistance may be corrected for moderatetemperature differences to what it would be at the reference temperature, as follows:RT 5 Rt11Tt 2T!where:RT = resistance at reference
32、temperature T,Rt = resistance as measured at temperature t,T = known or given temperature coefficient of resistance of the specimen being measured at reference temperature T,T = reference temperature, andt = temperature at which measurement is made.NOTE 1The parameter T, in the above equation, varie
33、s with conductivity and temperature. For copper of 100 % conductivity and a referencetemperature of 20C, its value is 0.00393. Values at other conductivities and temperatures will be found in NBS Handbook 100.4Table 1 lists temperaturecoefficients for the common electrical conductor materials.B193 1
34、638. Report8.1 For referee tests, report the following information:8.1.1 Identification of test specimen,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 micrometer readings, or8
35、.1.5.2 If by weighing, a record of length, weight, any density determinations that may be made, and calculated cross-sectionalareas.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 reference
36、 temperature, and8.1.11 Previous mechanical and thermal treatments. (Since the resistivity of a material usually depends upon them, these shallbe stated whenever the information is available.)8.2 For routine tests, only such of the items in 8.1 as apply to the particular case, or are significant, sh
37、all be reported.TABLE 3 Equivalent Resistivity Values for CopperAConductivity at20C (68F)percent IACS100.0Volume Resistivitycmil/ft 10.371mm2/m 0.017241in. 0.67879cm 1.7241Weight Resistivitylb/mile2 875.20g/m2 0.15328TABLE 1 Resistivity and Conductivity ConversionNOTE 1These factors are applicable o
38、nly to resistivity and conductivity values corrected to 20C (68F). They are applicable for any temperaturewhen used to convert between volume units only or between weight units only. Values of density, , for the common electrical conductor materials, arelisted in Table 2.Given NPerform indicatedoper
39、ationto obtain Volume Resistivity at 20C Weight Resistivity at 20C Conductivity at 20Ccmil/ft mm2/m in. cm lb/mile2 g/m2 % IACS(Volume Basis) % IACS(Weight Basis)Volume Resistivity at 20Ccmil/ft . . . N 601.52 N 15.279 N 6.0153 N 0.10535 (1/)N 601.53 (1/)(1/N) 1037.1 (1/N) 9220.0 (1/)mm2/m N 0.00166
40、24 . . . N 0.025400 N 0.010000 N 0.00017513 (1/)N (1/) (1/N) 1.7241 (1/N) 15.328 (1/)in. N 0.065450 N 39.370 . . . N 0.39370 N 0.0068950 (1/)N 39.370 (1/)(1/N) 67.879 (1/N) 603.45 (1/)cm N 0.16624 N 100.00 N 2.5400 . . . N 0.017513 (1/)N 100.00 (1/)(1/N) 172.41 (1/N) 1532.8 (1/)Weight Resistivity at
41、 20Clb/mile2 N 9.4924 N 5710.0 N 145.03 N 57.100 . . . N 5710.0 (1/N) 9844.8 (1/N) 87520g/m2 N 0.0016624 N N 0.025400 N 0.010000 N 0.00017513 . . . (1/N) 1.7241 (1/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 (1/N) 1.7241 . . . N 0.
42、11249 % IACS(weight basis)(1/N) 9220.0 (1/)(1/N) 15.328 (1/)(1/N) 603.45 (1/)(1/N) 1532.8 (1/)(1/N) 87520 (1/N) 15.328 N 8.89 (1/) . . .A The equivalent resistivity values for 100 % IACS (soft copper) were each computed from the fundamental IEC value (1/58 mm2/m) using conversion factors eachaccurat
43、e to at least seven significant figures. Corresponding values for other conductivities (aluminum, etc.) may be derived from these by multiplying by the reciprocalof the conductivity ratios and where applicable also by the density ratios, both accurate to at least seven significant figures.B193 164TA
44、BLE 2 Density and Temperature Coefficient of Resistance for Electrical Conductor MaterialsMaterial Approximate Density, at 20C, g/cm3TemperatureCoefficient ofResistance, , at20CMaterial Approximate Density, at 20C, g/cm3TemperatureCoefficient ofResistance, , at20CCopper, % IACS: Aluminum Alloy 8000,
45、101 8.89 0.00397 Specification B800, % IACS:100 8.89 0.00393 61.8 2.71 0.00408100 8.89 0.00393 61.8 2.71 0.0040898.40 8.89 0.00387 61.5 2.71 0.0040698.40 8.89 0.00387 61.5 2.71 0.0040698.16 8.89 0.00386 61.4 2.71 0.0040698.16 8.89 0.00386 61.4 2.71 0.0040697.80 8.89 0.00384 61.3 2.71 0.0040597.80 8.
46、89 0.00384 61.3 2.71 0.0040597.66 8.89 0.00384 61.2 2.71 0.0040497.66 8.89 0.00384 61.2 2.71 0.0040497.40 8.89 0.00383 61.0 2.71 0.0040397.40 8.89 0.00383 61.0 2.71 0.0040397.16 8.89 0.00382 60.9 2.71 0.0040297.16 8.89 0.00382 60.9 2.71 0.0040296.66 8.89 0.00380 60.8 2.71 0.0040296.66 8.89 0.00380 6
47、0.8 2.71 0.0040296.16 8.89 0.00378 60.7 2.71 0.0040196.16 8.89 0.00378 60.7 2.71 0.0040194.16 8.89 0.00370 60.6 2.71 0.0040094.16 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 0.00393Specification B298: 59.5 2.70 0.0039
48、3Class A 8.91 0.00393 59.0 2.70 0.00390Class A 8.91 0.00393 59.0 2.70 0.00390Class B 8.93 0.00393 57.0 2.70 0.00377Class B 8.93 0.00393 57.0 2.70 0.00377Class C 8.95 0.00394 56.5 2.70 0.00373Class C 8.95 0.00394 56.5 2.70 0.00373Class D 8.99 0.00394 56.0 2.70 0.00370Class D 8.99 0.00394 56.0 2.70 0.00370Class E 9.05 0.00395 55.0 2.70 0.00363Class E 9.05 0.00395 55.0 2.70 0.0036354.0 2.70 0.0035754.0 2.70 0.00357Nickel Coated Copper, 53.0 2.70 0.00350Nickel 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
