1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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This standard equation is used to compute the skin depth. An explanation can be found here.
Since data sources for materials properties typically present permeability in term of relative permeability (μr), that is what is used for input in the calculator.
Most typical materials used for signal and power carrying cables - e.g., copper, aluminum - have a relative permeability of 1. Materials with magnetic properties such as steel and iron have relative permeabilities ranging from hundreds to hundreds of thousands.
Here is a table of materials with values.
Numerical inputs are not error trapped.