ASTM E1004

Absolute probe coil methods, when used in conjunction with reference standards of known value, provide a means for determining the electrical conductivity of nonmagnetic materials.

Electrical conductivity of a sample can be used as a means of determining: (1) type of metal or alloy, (2) type of heat treatment (for aluminum this evaluation should be used in conjunction with a hardness examination), (3) aging of the alloy, (4) effects of corrosion, and (5) heat damage.

1. Scope

1.1 This test method covers a procedure for determining the electrical conductivity of nonmagnetic metals using the electromagnetic (eddy-current) method. The procedure has been written primarily for use with commercially available direct reading electrical conductivity instruments. General purpose eddy-current instruments may also be used for electrical conductivity measurements but will not be addressed in this test method.

1.2 This test method is applicable to metals that have either a flat or slightly curved surface and includes metals with or without a thin nonconductive coating.

1.3 Eddy-current determinations of electrical conductivity may be used in the sorting of metals with respect to variables such as type of alloy, aging, cold deformation, heat treatment, effects associated with non-uniform heating or overheating, and effects of corrosion. The usefulness of the examinations of these properties is dependent on the amount of electrical conductivity change caused by a change in the specific variable.

1.4 Electrical conductivity, when evaluated with eddy-current instruments, is usually expressed as a percentage of the conductivity of the International Annealed Copper Standard (IACS). The conductivity of the Annealed Copper Standard is defined to be 0.58 × 10⁸ S/m (100 % IACS) at 20°C.

1.5 The values stated in SI units are regarded as standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents

ASTM Standards
B193 Test Method for Resistivity of Electrical Conductor Materials
E105 Practice for Probability Sampling Of Materials
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
E1316 Terminology for Nondestructive Examinations
E543 Specification for Agencies Performing Nondestructive Testing
ASNT Documents
ANSI/ASNT-CP-189 Standard for Qualification and Certification of NDT Personnel
AIA Document
NAS–410 Certification and Qualification of Nondestructive Testing Personnel

Index Terms

eddy-current; electrical conductivity; metal sorting; nondestructive testing; Nonmagnetic metals; Probe methods; Silver (electrical/electronic applications); Railroad steel materials; Railroad steel materials--trolley wire; Silver-coated copper wire; Standard depth of penetration; Steel; Steel-reinforced electrical conductors; Steel wire strand; Temperature tests--image analysis instrumentation; Thickness; Tin-coated copper electrical wire; Trolley wire; Zinc alloys; Zinc-coated steel wire; Absolute coil method; Aluminum electrical conductors; Austenitic stainless steel; Bronze; Calibration--metals/alloys analysis instrumentation; Calibration--nondestructive analysis instrumentation; Coils; Communications; Conductance and conductivity (electrical); Copper electrical conductors; Copper (electromagnetic testing); Corrosion; Current measurement; Depth of penetration; Eddy current examination; Electromagnetic (eddy current) testing; Magnesium alloys; Metal electrical conductors; Nondestructive evaluation (NDE); Nonferrous metals/alloys; ICS Number Code 17.220.20 (Measurement of electrical and magnetic quantities)

Citing ASTM Standards

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