ASTM A932 / A932M - 01(2012)

    Standard Test Method for Alternating-Current Magnetic Properties of Amorphous Materials at Power Frequencies Using Wattmeter-Ammeter-Voltmeter Method with Sheet Specimens

    Active Standard ASTM A932 / A932M | Developed by Subcommittee: A06.01

    Book of Standards Volume: 03.04


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    Significance and Use

    4.1 This test method provides a satisfactory means of determining various ac magnetic properties of amorphous magnetic materials. It was developed to supplement the testing of toroidal and Epstein specimens. For testing toroidal specimens of amorphous materials, refer to Test Method A912/A912M.

    4.2 The procedures described herein are suitable for use by manufacturers and users of amorphous magnetic materials for materials specification acceptance and manufacturing control.

    Note 2This test method has been principally applied to the magnetic testing of thermally, magnetically annealed, and flattened amorphous strip at 50 and 60 Hz. Specific core loss at 13 or 14 kG [1.3 or 1.4T], specific exciting power at 13 or 14 kG [1.3 or 1.4T], and the flux density, B, at 1 Oe [79.6 A/m] are the recommended parameters for evaluating power grade amorphous materials.

    1. Scope

    1.1 This test method covers tests for various magnetic properties of flat-cast amorphous magnetic materials at power frequencies (50 and 60 Hz) using sheet-type specimens in a yoke-type test fixture. It provides for testing using either single- or multiple-layer specimens.

    Note 1This test method has been applied only at frequencies of 50 and 60 Hz, but with proper instrumentation and application of the principles of testing and calibration embodied in the test method, it is believed to be adaptable to testing at frequencies ranging from 25 to 400 Hz.

    1.2 This test method provides a test for specific core loss, specific exciting power and ac peak permeability at moderate and high flux densities, but is restricted to very soft magnetic materials with dc coercivities of 0.07 Oe [5.57 A/m] or less.

    1.3 The test method also provides procedures for calculating ac peak permeability from measured peak values of total exciting currents at magnetic field strengths up to about 2 Oe [159 A/m].

    1.4 Explanation of symbols and abbreviated definitions appear in the text of this test method. The official symbols and definitions are listed in Terminology A340.

    1.5 This test method shall be used in conjunction with Practice A34/A34M.

    1.6 The values stated in either 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.

    1.7 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials

    A340 Terminology of Symbols and Definitions Relating to Magnetic Testing

    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

    A876 Specification for Flat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel, Fully Processed Types

    A901 Specification for Amorphous Magnetic Core Alloys, Semi-Processed Types

    A912/A912M Test Method for Alternating-Current Magnetic Properties of Amorphous Materials at Power Frequencies Using Wattmeter-Ammeter-Voltmeter Method with Toroidal Specimens


    ICS Code

    ICS Number Code 17.220.20 (Measurement of electrical and magnetic quantities)

    UNSPSC Code

    UNSPSC Code 31380000(Magnets and magnetic materials)


    DOI: 10.1520/A0932_A0932M-01R12

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