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    ← Revision 50 as of 2018-07-18 17:58:39  ⇥ 
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$ \delta = \sqrt{ 2 \rho / \omega \mu_r \mu_0 } $ in m $ ~=~ \sqrt{ 2.533e11 \rho / f \mu_r } ~~$ in mm $ ~~~~~~ 2 / 2 \pi \mu_0 $ = 253303 m/H || Material || Temp || perm. || resis. ||<-7> depth (mm) at frequency (Hz) ||  | 
|| Material || Absolute<<BR>>Temperature || relative<<BR>>permeability || resistivity ||<-7> skin depth (mm) at frequency (Hz) || | 
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Resistivity - for copper see Matula 1979 page 1161, for aluminum see Simmons 1960 [[ attachment:skindepth.ods | LibreOffice Spreadsheet]]  | 
|| [[https://www.libreoffice.org | LibreOffice ]]<<BR>>[[ attachment:skindepth.ods | Spreadsheet]]  ||<-10|10> {{ https://upload.wikimedia.org/wikipedia/commons/f/f3/Skin_depth_by_Zureks.png }}            || ||$ { \Large { \delta = \sqrt{ 2 \rho \over { \omega ~ \mu_r ~ \mu_0 } } } } $<<BR>> in meters <<BR>><<BR>>$ { \Large { \delta = \sqrt{ 2.533e11 \rho \over { f ~\mu_r } } } } $<<BR>> in mm<<BR>><<BR>><<BR>>$ { \LARGE { { 2 \over { 2 \pi \mu_0 } } } } $ = 253303 m/H || || ~+'''Permeability'''+~<<BR>><<BR>>WAG, need citation<<BR>><<BR>> || || ~+'''Resistivity'''+~ <<BR>><<BR>> for copper see <<BR>>[[https://aip.scitation.org/doi/abs/10.1063/1.555614 | Matula 1979 ]]<<BR>>page 1161<<BR>><<BR>><<BR>>for aluminum see<<BR>> [[ https://journals.aps.org/pr/abstract/10.1103/PhysRev.117.62 | Simmons 1960 ]] || ||<)>Graph by [[https://commons.wikimedia.org/wiki/User:Zureks | Zureks]]<<BR>>from Wikipedia<<BR>>article [[ https://en.wikipedia.org/wiki/Skin_effect | skin effect ]] ||  | 
Skin Depth
Material  | 
   Absolute  | 
   relative  | 
  resistivity  | 
  skin depth (mm) at frequency (Hz)  | 
||||||
  | 
  K  | 
  \mu_r  | 
  \rho~~\Omega-m  | 
  1 Hz  | 
  60 Hz  | 
  400 Hz  | 
  1 KHz  | 
  5 KHz  | 
  20 KHz  | 
  200 KHz  | 
3% Si Transformer Steel  | 
  300  | 
  700  | 
  5e-7  | 
  13  | 
  1.7  | 
  0.67  | 
  0.43  | 
  0.19  | 
  0.95  | 
  0.030  | 
3% Si Transformer Steel  | 
  600  | 
  300?  | 
  7e-7?  | 
  24  | 
  3.1  | 
  1.2  | 
  0.77  | 
  0.34  | 
  0.17  | 
  0.054  | 
Copper  | 
  300  | 
  1  | 
  1.7e-8  | 
  66  | 
  8.5  | 
  3.3  | 
  2.1  | 
  0.93  | 
  0.46  | 
  0.15  | 
Copper  | 
  600  | 
  1  | 
  3.8e-8  | 
  98  | 
  13  | 
  4.9  | 
  3.1  | 
  1.4  | 
  0.69  | 
  0.22  | 
Aluminum  | 
  300  | 
  1  | 
  2.8e-8  | 
  84  | 
  11  | 
  4.2  | 
  2.7  | 
  1.2  | 
  0.60  | 
  0.19  | 
Aluminum  | 
  600  | 
  1  | 
  5.9e-8  | 
  122  | 
  16  | 
  6.1  | 
  3.9  | 
  1.7  | 
  0.86  | 
  0.27  | 
   | 
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 { \Large { \delta = \sqrt{ 2 \rho \over { \omega ~ \mu_r ~ \mu_0 } } } }   | 
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 Permeability  | 
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 Resistivity   | 
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Graph by Zureks  | 
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