Note 1 to entry: $\lambda$ is a function of temperature.

Note 2 to entry: In English, "penetration depth" has a different meaning for an electromagnetic wave (see IEV 705-03-25).

Note 3 to entry: In French, "profondeur de pénétration" has different meanings for an electromagnetic wave (see IEV 705-03-25), for current density (see IEV 726-07-06), and in industrial electroheat (see IEV 841-27-21).

Note 4 to entry: This entry was numbered 815-10-33 in IEC 60050-815:2015.