ASTM A773/A773M-14

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 normal induction and dc hysteresis (B-H loop) 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 semihard 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 (permanent magnet) materials.  
5.3 Hysteresigraphs are not recommended for measurement of initial permeability 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 (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 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2014
• ICS: 29.030 - Magnetic materials
• Technical Committee: A06 - Magnetic Properties
• Drafting Committee: A06.01 - Test Methods

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: A773/A773M − 14
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 A34/A34MPractice for Sampling and Procurement Testing
of Magnetic Materials
1.1 This test method provides dc hysteresigraph procedures
A340Terminology of Symbols and Definitions Relating to
(B-H loop methods) for the determination of basic magnetic
Magnetic Testing
properties of materials in the form of ring, spirally wound
A341/A341MTest Method for Direct Current Magnetic
toroidal, link, double-lapped Epstein cores, or other standard
Properties of Materials Using D-C Permeameters and the
shapes that may be cut, stamped, machined, or ground from
Ballistic Test Methods
cast, compacted, sintered, forged, or rolled materials. It in-
A343/A343MTest Method for Alternating-Current Mag-
cludes tests for normal induction and hysteresis loop determi-
netic Properties of Materials at Power Frequencies Using
nation taken under conditions of continuous sweep magnetiza-
Wattmeter-Ammeter-Voltmeter Method and 25-cm Ep-
tion. Rate of sweep may be varied, either manually or
stein Test Frame
automatically at different portions of the curves during mea-
A596/A596MTest Method for Direct-Current Magnetic
surement.
Properties of Materials Using the Ballistic Method and
1.2 The equipment and procedures described in this test
Ring Specimens
method are most suited for soft and semi-hard materials with
A977/A977MTestMethodforMagneticPropertiesofHigh-
intrinsic coercivity less than about 100 Oersteds [8 kA/M].
Coercivity Permanent Magnet Materials Using Hyster-
Materials with higher intrinsic coercivities should be tested
esigraphs
according to Test Method A977/A977M.
E691Practice for Conducting an Interlaboratory Study to
1.3 The values and equations stated in customary (cgs-emu Determine the Precision of a Test Method
and inch-pound) or SI units are to be regarded separately as
2.2 Other:
standard. Within this standard, SI units are shown in brackets.
IEC Publication 60404-4 Ed 2.2 – Part 4:Methods of
Thevaluesstatedineachsystemmaynotbeexactequivalents;
Measurement of d.c. Magnetic Properties of Magnetically
3
therefore,eachsystemshallbeusedindependentlyoftheother.
Soft Materials (2008)
Combiningvaluesfromthetwosystemsmayresultinnoncon-
formance with this standard.
3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions—The terms and symbols used in this test
safety concerns, if any, associated with its use. It is the
method are defined in Terminology A340.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Summary of Test Method
bility of regulatory limitations prior to use.
4.1 A specimen is wound with a magnetizing winding (the
primary winding) and a search winding (the secondary wind-
2. Referenced Documents
2 ing) for measuring the change in flux. When a magnetizing
2.1 ASTM Standards:
current, I, is applied to the primary winding, a magnetic field,
H, is produced in the coil. This in turn produces magnetic flux
1
This test method is under the jurisdiction of ASTM Committee A06 on
φ in the specimen and the changing flux induces a voltage in
MagneticPropertiesandisthedirectresponsibilityofSubcommitteeA06.01onTest
the secondary winding which is integrated with respect to time
Methods.
using a fluxmeter. In specimens with uniform cross-sectional
Current edition approved Oct. 1, 2014. Published October 2014. Originally
area that do not contain air gaps, such as rings, all of the
approved in 1980. Last previous edition approved in 2009 as A773/A773M–01
(2009). DOI: 10.1520/A0773_A0773M-14.
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
3
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute, 25 W. 43rd St., 4th
the ASTM website. 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 − 14
FIG. 1 Block Diagram of Ring Test Apparatus
1
magnetizing current is used to magnetize the specimen, and H
E 5 edt (3)
*
is proportional to I in accordance with the following equation: RC
H 5 KI (1)
where:
E = output voltage, V;
where:
R = inp
...

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 − 01 (Reapproved 2009) A773/A773M − 14
Standard Test Method for
dc Direct Current Magnetic Properties of Materials Using
Ring and Permeameter Procedures with dc Electronic Low
1
Coercivity 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 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 tracing. Total elapsed time for tracing a hysteresis
loop is commonly 10 to 120 s per loop. 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 stated in either SI units or inch-pound units 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 non-conformancenonconformance with thethis 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 and health practices and determine the applicability of regulatory
limitations prior to use.
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 Materials Using D-C Permeameters and the Ballistic Test
Methods
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 404-4:60404-4 Ed 2.2 – Part 4: Magnetic Materials—Part 4: Methods of Measurement of dcd.c. Magnetic
3
Properties of Iron and Steel (1995)Magnetically Soft Materials (2008)
3. Terminology
3.1 Definitions—The terms and symbols used in this test method are defined in Terminology A340.
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 May 1, 2009Oct. 1, 2014. Published August 2009October 2014. Originally approved in 1980. Last previous edition approved in 20012009 as
A773/A773M–01. –01 (2009). DOI: 10.1520/A0773_A0773M-01R09.10.1520/A0773_A0773M-14.
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 National Standards Institute, 25 W. 43rd St., 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
A773/A773M − 14
4. Summary of Test Method
4.1 As in making most magnetic measurements, a A specimen is wound with an excitinga magnetizing
...