a value for conductivity agreed in 1913 with copper being given the value of 100%, equivalent to 58MS/m or a mass resistivity of 0.15176 Ωg/m2. Advances in refining mean that high conductivity copper is now frequently of 101% conductivity or higher.
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Note: Through this standard, copper sets the reference for conductivity of metals. Other metals' conductivity is expressed as a percentage of the conductivity of copper.
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