Note 1 to entry: The AC magnetization, $M\left(t\right)$ , under the magnetic field strength of $h_0\text{cos}\omega t$ is expanded as: $M\left(t\right)=h_0{\displaystyle \sum _{n=0}^{\infty }\left[{\kappa }_n^{\text{'}}\text{cos}\left(n\omega t\right)+{\kappa }_n^{"}\text{sin}\left(n\omega t\right)\right]}$

where ${\kappa }_n^{\text{'}}$ and ${\kappa }_n^{"}$ are the real and imaginary parts of the AC magnetic susceptibility for the order $n$ .

Note 2 to entry: The fundamental components ${\kappa }_1^{\text{'}}$ and ${\kappa }_1^{"}$ are mostly observed for measurements of superconducting transition.

Note 3 to entry: The AC energy loss density $W$ is given as:

$W=\pi {\mu }_0{h}_0^2{\kappa }_1^{"}$.

Note 4 to entry: This entry was numbered 815-17-13 in IEC 60050-815:2015.