ASTM E703-20

Standard Practice for Electromagnetic (Eddy Current) Sorting of Nonferrous Metals

SIGNIFICANCE AND USE
5.1 Absolute and comparative methods provide a measure for sorting large quantities of nonferrous parts or stock with regard to composition or condition, or both.  
5.2 The comparative or two-coil method is used when high-sensitivity examination is required. The advantage of this method is that it almost completely suppresses interferences.  
5.3 The ability to accomplish these types of separations satisfactorily is dependent upon the relation of the electric characteristics of the nonferrous parts to their physical condition.  
5.4 These methods may be used for high-speed sorting in a fully automated setup where the speed of examination may approach many specimens per second depending on their size and shape.  
5.5 Successful sorting of nonferrous material depends mainly on the variables present in the sample and the proper selection of frequency and fill factor.  
5.6 The accuracy of a sort will be affected greatly by the coupling between the test coil field and the examined part during the measuring period.
SCOPE
1.1 This practice describes a procedure for sorting nonferrous metals using the electromagnetic (eddy current) method. The procedure is intended for use with instruments using absolute or comparator-type coils for distinguishing variations in mass, shape, conductivity, and other variables such as alloy, heat treatment, or hardness that may be closely correlated with the electrical properties of the material. Selection of samples to evaluate sorting feasibility and to establish standards is also described.  
1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-May-2020
• ICS: 77.120.01 - Non-ferrous metals in general
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.07 - Electromagnetic Method

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E703 − 20
Standard Practice for
Electromagnetic (Eddy Current) Sorting of Nonferrous
1
Metals
This standard is issued under the fixed designation E703; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
3
1. Scope* 2.2 ASNT Documents:
SNT-TC-1A Recommended Practice for Personnel Qualifi-
1.1 This practice describes a procedure for sorting nonfer-
cation and Certification in Nondestructive Testing
rous metals using the electromagnetic (eddy current) method.
ANSI/ASNT CP-189 Standard for Qualification and Certifi-
The procedure is intended for use with instruments using
cation of Nondestructive Testing Personnel
absolute or comparator-type coils for distinguishing variations
4
2.3 AIA Standard:
in mass, shape, conductivity, and other variables such as alloy,
NAS-410 Qualification and Certification of Nondestructive
heat treatment, or hardness that may be closely correlated with
Testing Personnel
the electrical properties of the material. Selection of samples to
evaluate sorting feasibility and to establish standards is also
3. Terminology
described.
3.1 Standard terminology relating to electromagnetic ex-
1.2 This standard does not purport to address all of the
amination may be found in Terminology E1316, Section C:
safety concerns, if any, associated with its use. It is the
Electromagnetic Testing.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Summary of Practice
mine the applicability of regulatory limitations prior to use.
4.1 The techniques that are primarily used in electromag-
1.3 This international standard was developed in accor-
netic sorting employ the absolute (single-) and comparative
dance with internationally recognized principles on standard-
(two-) coil methods using either encircling or probe coils. The
ization established in the Decision on Principles for the
decision of whether to use single-coil or two-coil operation is
Development of International Standards, Guides and Recom-
usually based on empirical data. In the absolute-coil method
mendations issued by the World Trade Organization Technical
(encircling or probe), the equipment is standardized by placing
Barriers to Trade (TBT) Committee.
standards of known properties in the test coil. The value of the
examined electrical parameter, which may be correlated with
2. Referenced Documents
alloy, heat treatment temper, or hardness, is read on the display
2
of an indicator. In the comparative coil method (encircling or
2.1 ASTM Standards:
probe coils), the test specimen in one coil is compared with a
E105 Practice for Probability Sampling of Materials
reference standard in a second coil to determine whether the
E122 Practice for Calculating Sample Size to Estimate,With
test specimen is within or outside of the required limits.
Specified Precision, the Average for a Characteristic of a
4.1.1 Absolute Coil Method:
Lot or Process
4.1.1.1 Encircling Coil—Various reference standards are
E543 Specification forAgencies Performing Nondestructive
inserted consecutively in the test coil, and the controls of the
Testing
instrument are adjusted to obtain an appropriate response.
E1316 Terminology for Nondestructive Examinations
Typically, three samples would be used representing the upper,
lower, and mid-range for which standardization is required.
The examination is then conducted by inserting the specimens
1
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
to be sorted into the test coil, and observing the instrument
structive Testing and is the direct responsibility of Subcommittee E07.07 on
response.
Electromagnetic Method.
CurrenteditionapprovedJune1,2020.PublishedJuly2020.Originallyapproved
in 1979. Last previous edition approved in 2014 as E703 – 14. DOI: 10.1520/
3
E0703-20. AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
4
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available fromAerospace IndustriesAssociation ofAmerica, Inc. (AIA), 1000
Standards volume information, refer to the standard’s Document Summary page on WilsonBlvd.,Suite1700,Arlington,VA22209-3928,http://www.aia-aerospace.org.
the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright
...

This document is not 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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E703 − 14 E703 − 20
Standard Practice for
Electromagnetic (Eddy Current) Sorting of Nonferrous
1
Metals
This standard is issued under the fixed designation E703; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This practice describes a procedure for sorting nonferrous metals using the electromagnetic (eddy current) method. The
procedure is intended for use with instruments using absolute or comparator-type coils for distinguishing variations in mass, shape,
conductivity, and other variables such as alloy, heat treatment, or hardness that may be closely correlated with the electrical
properties of the material. Selection of samples to evaluate sorting feasibility and to establish standards is also described.
1.2 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
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
E543 Specification for Agencies Performing Nondestructive Testing
E1316 Terminology for Nondestructive Examinations
3
2.2 ASNT Documents:
SNT-TC-1A Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing
ANSI/ASNT CP-189 Standard for Qualification and Certification of Nondestructive Testing Personnel
4
2.3 AIA Standard:
NAS-410 Qualification and Certification of Nondestructive Testing Personnel
3. Terminology
3.1 Standard terminology relating to electromagnetic examination may be found in Terminology E1316, Section C:
Electromagnetic Testing.
4. Summary of Practice
4.1 The techniques that are primarily used in electromagnetic sorting employ the absolute (single-) and comparative (two-) coil
methods using either encircling or probe coils. The decision of whether to use single-coil or two-coil operation is usually based
on empirical data. In the absolute-coil method (encircling or probe), the equipment is standardized by placing standards of known
properties in the test coil. The value of the examined electrical parameter, which may be correlated with alloy, heat treatment
1
This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.07 on Electromagnetic
Method.
Current edition approved June 1, 2014June 1, 2020. Published July 2014July 2020. Originally approved in 1979. Last previous edition approved in 20092014 as
E703 - 09.E703 – 14. DOI: 10.1520/E0703-14.10.1520/E0703-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
4
Available from Aerospace Industries Association of America, Inc. (AIA), 1000 Wilson Blvd., Suite 1700, Arlington, VA 22209-3928, http://www.aia-aerospace.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E703 − 20
temper, or hardness, is read on the display of an indicator. In the comparative coil method (encircling or probe coils), the test
specimen in one coil is compared with a reference standard in a second coil to determine whether the test specimen is within or
outside of the required limits.
4.1.1 Absolute Coil Method:
4.1.1.1 Encircling Coil—Various reference standards are
...