Standard Test Method for AC Magnetic Permeability of Materials Using Sinusoidal Current

Importancia y uso:

4.1 The permeability determined by this method is the impedance permeability. Impedance permeability is the ratio of the peak value of flux density (B_max) to the assumed peak magnetic field strength (H_z) without regard to phase. As compared to testing under sinusoidal flux (sinusoidal B) conditions, the permeabilities determined by this method are numerically lower since, for a given test signal frequency, the rate of flux change (dB/dt) is higher.

4.2 This test method is suitable for impedance permeability measurements at very low magnetic inductions at power frequencies (50 Hz to 60 Hz) to moderate inductions below the point of maximum permeability of the material (the knee of the magnetization curve) or until there is visible distortion of the current waveform. The lower limit is a function of sample area, secondary turns, and the sensitivity of the flux-reading voltmeter used. At higher inductions, measurements of flux-generated voltages that are appreciably distorted mean that the flux has appreciable harmonic frequency components. The upper limit is given by the availability of pure sinusoidal current, which is a function of the power source. In addition, a large ratio (≥10) of the total series resistance of the primary circuit to the primary coil impedance is required. With proper test apparatus, this test method is suitable for use at frequencies up to 1 MHz.

4.3 This test method is suitable for design, specification acceptance, service evaluation, quality control, and research use.

Subcomité:

A06.01

Referida por:

A0340-23A, A0753-21

Volúmen:

03.07

Número ICS:

29.030 (Magnetic materials)

Palabras clave:

magnetic field strength; magnetic flux density; magnetic induction; permeability; sinusoidal current; toroidal core;