ASTM A341/A341M-16(2022)
Standard Test Method for Direct Current Magnetic Properties of Soft Magnetic Materials Using D-C Permeameters and the Point by Point (Ballistic) Test Methods

Standard No.

ASTM A341/A341M-16(2022)

Release Date

2022

Published By

American Society for Testing and Materials (ASTM)

Latest

ASTM A341/A341M-16(2022)

Scope

1.1 This test method provides dc permeameter tests for the basic magnetic properties of soft magnetic materials in the form of bars, rods, wire, or strip specimens which may be cut, machined, or ground from cast, compacted, sintered, forged, extruded, rolled, or other fabricated materials. It includes tests for determination of the normal induction under symmetrically cyclically magnetized (SCM) conditions and the hysteresis loop (B-H loop) taken under conditions of rapidly changing or steep wavefront reversals of the direct current magnetic field strength. This method has been historically referred to as the ballistic test method. For testing hard or permanent magnet materials, Test Method A977/A977M shall be used. 1.2 This test method shall be used in conjunction with Practice A34/A34M. 1.3 This test method covers a range of magnetic field strength in the specimen from about 0.05 Oe [4 A/m] up to above 5000 Oe [400 kA/m] through the use of several permeameters. The separate permeameters cover this test region in several overlapping ranges. 1.4 Normal induction and hysteresis properties may be determined over the magnetic flux density range from essentially zero to the saturation induction for most materials. 1.5 Recommendations of the useful magnetic field strength range for each of the permeameters are shown in Table 1.2 Permeameters particularly well suited for general testing of soft magnetic materials are shown in boldface. Also, see Sections 3 and 4 for general limitations relative to the use of permeameters. 1.6 The symbols and abbreviated definitions used in this test method appear with Fig. 1 and in appropriate sections of this document. For the official definitions, see Terminology A340. Note that the term magnetic flux density used in this document is synonymous with the term magnetic induction. 1.7 Warning—Mercury has been designated by EPA and many state agencies as a hazardous material that can cause central nervous system, kidney, and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury-containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s website (http://www.epa.gov/mercury/faq.htm ) for additional information. Users should be aware that selling mercury or mercurycontaining products, or both, in your state may be prohibited by state law. 1.8 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 except for the sections concerning calculations where there are separate sections for the respective unit systems. 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. 1.9 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. 1.10 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. 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, 2022. Published October 2022. Originally approved in 1969. Last previous edition approved in 2016 as A341/A341M – 16. DOI: 10.1520/A0341_A0341M-16R22. 2 The boldface numbers in parentheses refer to a list of references at the end of this standard. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States 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. 1 TABLE 1 Permeameters Permeameter Useful Magnetic Field Strength RangeA H Measuring DeviceB Reluctance Compensation Magnetizing Coil Surrounds Specimen ReferencesD Oe kA/m Babbit 40/1000 3.2/80 I, HC yes yes (1,2) Burroughs 0.1/300 0.008/24 I yes yes (1,3,4,5) Fahy SimplexC 0.1/300 0.008/24 HC no no (1,4,5,6,7) Fahy Simplex Super H adapterC 100/2500 8/200 HC no no (1,3) Full range 0.05/1400 0.004/112 HC yes yes (1,8) High H 100/5000 8/400 FC yes no (1,5,7,9) Iliovici 0.5/500 0.04/400 I, HC yes yes (4,10,11) IEC Type A 0.1/2500 0.008/200 HC, HP no yes IEC 60404-4 IEC Type B 0.1/630 0.008/50 RCC no no IEC 60404-4 Isthmus 100/20 000+ 8/1600+ HC, HP no no (1,4,12,13) MH 0.1/300 0.008/24 FC yes yes (1,6,14) NPL 0.5/2500 0.04/200 I, HC yes yes (15) Saturation 100/4000 8/320 HC no yes (5,16,17) A Although the permeameters are capable of being used at the lower end of the measurement range, the measurement accuracy is reduced. B I—magnetizing current; HC—fixed H coil; FC—flip coil; HP—Hall probe; RCC —Rogowski-Chattock coil. C Fahy permeameters require a standard of known magnetic properties for calibration of the H coil. D The boldface numbers in parentheses refer to a list of references at the end of this standard. NOTE 1— A1—Multirange ammeter (main current) A2—Multirange ammeter (hysteresis current) B—Magnetic flux density test position for Switch S3 F—Electronic Fluxmeter H—Magnetic field strength test position for Switch S3 N1—Magnetizing coil N2—Magnetic flux sensing (B) coil N3—Magnetic field strength (H) sensing coil R1—Main current control rheostat R2—Hysteresis current control rheostat S1—Reversing switch for magnetizing current S2—Shunting switch for hysteresis current control rheostat S3—Fluxmeter selector switch SP—Specimen FIG. 1 Basic Circuit Using Permeameter A341/A341M − 16 (2022) 2 

ASTM A341/A341M-16(2022) Referenced Document

• ASTM A34/A34M Standard Practice for Sampling and Procurement Testing of Magnetic Materials
• ASTM A340 Standard Terminology of Symbols and Definitions Relating to Magnetic Testing
• ASTM A596/A596M Standard Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring Specimens
• ASTM A977/A977M Standard Test Method for Magnetic Properties of High-Coercivity Permanent Magnet Materials Using Hysteresigraphs

ASTM A341/A341M-16(2022) history

• 2022 ASTM A341/A341M-16(2022) Standard Test Method for Direct Current Magnetic Properties of Soft Magnetic Materials Using D-C Permeameters and the Point by Point (Ballistic) Test Methods
• 2016 ASTM A341/A341M-16 Standard Test Method for Direct Current Magnetic Properties of Soft Magnetic Materials Using D-C Permeameters and the Point by Point (Ballistic) Test Methods
• 2000 ASTM A341/A341M-00(2011)e1 Standard Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods
• 2000 ASTM A341/A341M-00(2011) Standard Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods
• 2000 ASTM A341/A341M-00(2005)e1 Standard Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods
• 2005 ASTM A341/A341M-00(2005) Standard Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods
• 2000 ASTM A341/A341M-00 Standard Test Method for Direct Current Magnetic Properties of Materials Using D-C Permeameters and the Ballistic Test Methods