ASTM International

Standard Test Methods for Permeability of Weakly Magnetic Materials
 N A342/A342M

Annotation

These test methods cover four procedures for determination of the permeability [relative permeability]2 of materials having a permeability not exceeding 6.0.

The test methods covered are as follows:

Test Method 1—Fluxmetric Method is suitable for materials with permeabilities between 1.0 and 4.0. This method permits the user to select the magnetic field strength at which the permeability is to be measured.

Test Method 2—Permeability of Paramagnetic Materials has been eliminated as an acceptable method of test.

Test Method 3—Low Mu Permeability Indicator is suitable for measuring the permeability of a material as "less than" or "greater than" that of calibrated standard inserts with permeability between 1.01 and 6.0, as designated for use in a Low-Mu Permeability Indicator.3 In this method, a small volume of specimen is subjected to a local magnetic field that varies in magnitude and direction, so it is not possible to specify the magnetic field strength at which the measurement is made.

Test Method 4—Flux Distortion is suitable for materials with permeability between 1.0 and 2.0. In this method, a small volume of specimen is subjected to a local magnetic field

that varies in magnitude and direction, so it is not possible to specify the magnetic field strength at which the measurement is made.4

Test Method 5—Vibrating Sample Magnetometry is suitable for materials with permeability between 1.0 and 4.0. This test method permits the user to select the magnetic field strength at which the permeability is to be measured.