Skin Depth
\delta = \sqrt{ 2 \rho / \omega \mu_r \mu_0 } . . . . . 2 / \mu_0 = 1.59e6 m/H
Material |
Temp |
perm. |
resis. |
depth (m) at frequency |
|||||
|
K |
\mu_r |
\rho~~\Omega-m |
60 Hz |
400 Hz |
1 KHz |
5 KHz |
20 KHz |
200 KHz |
3% Si Transformer Steel |
300 |
700 |
5e-7 |
|
|
|
|
|
|
3% Si Transformer Steel |
600 |
300? |
7e-7? |
|
|
|
|
|
|
Aluminum |
300 |
1 |
2.8e-8 |
|
|
|
|
|
|
Aluminum |
600 |
1 |
|
|
|
|
|
|
|
Copper |
300 |
1 |
1.7e-8 |
|
|
|
|
|
|
Copper |
600 |
1 |
3.8e-8 |
|
|
|
|
|
|
Resistivity - see Matula 1979 page 1161