ASTM A773/A773M-21

Standard Test Method for Direct Current Magnetic Properties of Low Coercivity Magnetic Materials Using Hysteresigraphs

SIGNIFICANCE AND USE
5.1 Hysteresigraphs permit more rapid and efficient collection of data as compared to the point by point ballistic Test Methods A341/A341M and A596/A596M. The high measurement point density offered by computer-automated systems is often required for computer aided design of electrical components such as transformers, motors, and relays.  
5.2 Hysteresigraphs are particularly desirable for testing of semi-hard and hard magnetic materials, where either the entire second quadrant (demagnetization curve) or entire hysteresis loop is of primary concern. Test Method A977/A977M describes the special requirements for accurate measurement of hard magnetic (permanent magnet) materials.  
5.3 Hysteresigraphs are not recommended for measurement of initial permeability, µi, of materials with high magnetic permeability such as nickel-iron, amorphous, and nanocrystalline materials due to errors associated with integrator drift; in these cases, Test Method A596/A596M is a more appropriate method.  
5.4 Provided the test specimen is representative of the bulk sample or lot, this test method is well suited for design, specification acceptance, service evaluation, and research and development.
SCOPE
1.1 This test method provides dc hysteresigraph procedures for the determination of basic magnetic properties of materials in the form of ring, spirally wound toroidal, link, double-lapped Epstein cores, or other standard shapes that may be cut, stamped, machined, or ground from cast, compacted, sintered, forged, or rolled materials. It includes tests for initial and normal magnetization curves and hysteresis loop determination taken under conditions of continuous sweep magnetization. Rate of sweep may be varied, either manually or automatically at different portions of the curves during measurement.  
1.2 The equipment and procedures described in this test method are most suited for soft and semi-hard materials with intrinsic coercivity less than about 100 Oersteds [8 kA/M]. Materials with higher intrinsic coercivities should be tested according to Test Method A977/A977M.  
1.3 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this standard, SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this standard.  
1.4 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.  
1.5 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-Jan-2021
• ICS: 29.030 - Magnetic materials
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.01 - Test Methods

Relations

• Refers: ASTM A977/A977M-07(2020) - Standard Test Method for Magnetic Properties of High-Coercivity Permanent Magnet Materials Using Hysteresigraphs
• Effective Date: 01-Jun-2020

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: A773/A773M − 21
Standard Test Method for
Direct Current Magnetic Properties of Low Coercivity
1
Magnetic Materials Using Hysteresigraphs
This standard is issued under the fixed designationA773/A773M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method provides dc hysteresigraph procedures
A34/A34MPractice for Sampling and Procurement Testing
for the determination of basic magnetic properties of materials
of Magnetic Materials
in the form of ring, spirally wound toroidal, link, double-
A340Terminology of Symbols and Definitions Relating to
lappedEpsteincores,orotherstandardshapesthatmaybecut,
Magnetic Testing
stamped, machined, or ground from cast, compacted, sintered,
A341/A341MTest Method for Direct Current Magnetic
forged, or rolled materials. It includes tests for initial and
Properties of Soft Magnetic Materials Using D-C Per-
normalmagnetizationcurvesandhysteresisloopdetermination
taken under conditions of continuous sweep magnetization. meametersandthePointbyPoint(Ballistic)TestMethods
A343/A343MTest Method for Alternating-Current Mag-
Rateofsweepmaybevaried,eithermanuallyorautomatically
at different portions of the curves during measurement. netic Properties of Materials at Power Frequencies Using
Wattmeter-Ammeter-Voltmeter Method and 25-cm Ep-
1.2 The equipment and procedures described in this test
stein Test Frame
method are most suited for soft and semi-hard materials with
A596/A596MTest Method for Direct-Current Magnetic
intrinsic coercivity less than about 100 Oersteds [8 kA/M].
Properties of Materials Using the Ballistic Method and
Materials with higher intrinsic coercivities should be tested
Ring Specimens
according to Test Method A977/A977M.
A977/A977MTestMethodforMagneticPropertiesofHigh-
1.3 The values and equations stated in customary (cgs-emu
Coercivity Permanent Magnet Materials Using Hyster-
and inch-pound) or SI units are to be regarded separately as
esigraphs
standard. Within this standard, SI units are shown in brackets.
E691Practice for Conducting an Interlaboratory Study to
Thevaluesstatedineachsystemmaynotbeexactequivalents;
Determine the Precision of a Test Method
therefore,eachsystemshallbeusedindependentlyoftheother.
2.2 Other:
Combiningvaluesfromthetwosystemsmayresultinnoncon-
IEC Publication 60404-4 Ed 2.2 – Part 4:Methods of
formance with this standard.
Measurement of d.c. Magnetic Properties of Magnetically
3
Soft Materials (2008)
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions—The terms and symbols used in this test
priate safety, health, and environmental practices and deter-
method are defined in Terminology A340.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
4.1 A specimen is wound with a magnetizing winding (the
ization established in the Decision on Principles for the
primary winding) and a search winding (the secondary wind-
Development of International Standards, Guides and Recom-
ing) for measuring the change in flux. When a magnetizing
mendations issued by the World Trade Organization Technical
current, I, is applied to the primary winding, a magnetic field,
Barriers to Trade (TBT) Committee.
H, is produced in the coil. This in turn produces magnetic flux
1 2
This test method is under the jurisdiction of ASTM Committee A06 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
MagneticPropertiesandisthedirectresponsibilityofSubcommitteeA06.01onTest contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Methods. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 1, 2021. Published February 2021. Originally the ASTM website.
3
approved in 1980. Last previous edition approved in 2014 as A773/A773M–14. Available from American National Standards Institute, 25 W. 43rd St., 4th
DOI: 10.1520/A0773_A0773M-21. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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A773/A773M
...

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: A773/A773M − 14 A773/A773M − 21
Standard Test Method for
Direct Current Magnetic Properties of Low Coercivity
1
Magnetic Materials Using Hysteresigraphs
This standard is issued under the fixed designation A773/A773M; 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 test method provides dc hysteresigraph procedures (B-H loop methods) for the determination of basic magnetic properties
of materials in the form of ring, spirally wound toroidal, link, double-lapped Epstein cores, or other standard shapes that may be
cut, stamped, machined, or ground from cast, compacted, sintered, forged, or rolled materials. It includes tests for normal induction
initial and normal magnetization curves and hysteresis loop determination taken under conditions of continuous sweep
magnetization. Rate of sweep may be varied, either manually or automatically at different portions of the curves during
measurement.
1.2 The equipment and procedures described in this test method are most suited for soft and semi-hard materials with intrinsic
coercivity less than about 100 Oersteds [8 kA/M]. Materials with higher intrinsic coercivities should be tested according to Test
Method A977/A977M.
1.3 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard.
Within this standard, SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each
system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this
standard.
1.4 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.
1.5 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:
A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials
A340 Terminology of Symbols and Definitions Relating to Magnetic Testing
A341/A341M Test Method for Direct Current Magnetic Properties of Soft Magnetic Materials Using D-C Permeameters and the
Point by Point (Ballistic) Test Methods
1
This test method is under the jurisdiction of ASTM Committee A06 on Magnetic Properties and is the direct responsibility of Subcommittee A06.01 on Test Methods.
Current edition approved Oct. 1, 2014Feb. 1, 2021. Published October 2014February 2021. Originally approved in 1980. Last previous edition approved in 20092014 as
A773/A773MA773/A773M – 14.–01 (2009). DOI: 10.1520/A0773_A0773M-14.10.1520/A0773_A0773M-21.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
A773/A773M − 21
A343/A343M Test Method for Alternating-Current Magnetic Properties of Materials at Power Frequencies Using Wattmeter-
Ammeter-Voltmeter Method and 25-cm Epstein Test Frame
A596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
A977/A977M Test Method for Magnetic Properties of High-Coercivity Permanent Magnet Materials Using Hysteresigraphs
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 Other:
IEC Publication 60404-4 Ed 2.2 – Part 4: Methods of Measurement of d.c. Magnetic Properties of Magnetically Soft Materials
3
(2008)
3. Terminology
3.1 Definitions—The terms and symbols used in this test method are defined in Terminology A340.
4. Summary of Test Method
4.1 A specimen is wound with a magnetizing winding (the primary wi
...