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

Standard No.

ASTM A341/A341M-16

Release Date

2016

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM A341/A341M-16(2022)

Latest

ASTM A341/A341M-16(2022)

Scope

3.1 Permeameters require the use of yokes to complete the magnetic circuit and are therefore inherently less accurate than ring test methods. Refer to Test Method A596/A596M for further details on ring test methods. However, when testing certain shapes as bars or when magnetic field strength in excess of 200 Oe [16 kA/m] is required, permeameters are the only practical means of measuring magnetic properties.

3.2 This test method is suitable for specification acceptance, service evaluation, research and development and design.

3.3 When the test specimen is fabricated from a larger sample and is in the same condition as the larger sample, it may not exhibit magnetic properties representative of the original sample. In such instances the test results, when viewed in context of past performance history, will be useful for judging the suitability of the material for the intended application.

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.

(A) Although the permeameters are capable of being used at the lower end of the measurement range, the measurement accuracy is reduced.

(B)

ASTM A341/A341M-16 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 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