Magnetic Permeability

Magnetic measurement principle — Principle of the sample cell for magnetic material measurements.

Novocontrol offers in addition to dielectric- and impedance measurements magnetic materials measurements.

For this purpose, the Novocontrol dielectric/impedance RF sample cell is replaced by a magnetic cell. It is mounted at the RF extension line of the RF extension system which operates between 1Mhz and 3 GHz (8 GHz option).

The sample must have the geometry of a cylindrical ring. It is placed centered in the magnetic cell as shown left. If the sample cell is completely filled by the sample material, the magnetic permeability μ^* of the sample material can be calculated from the complex sample inductivity by eqn. (2).

µ^*=µ'-jµ" (1)

µ^*=L^*/L₀; (2)

L^*=jωZ^* (3)

In practice, the sample material must not completely fill the cell. In this case the inductivity of the not filled cell volume is subtracted from the measurement impedance in eqn. (2).

Magnetic material properties can also be determined under computer control with or without temperature control as these measurements are available as an option of the Novocontrol standard software WinDeta.