Conductivity -commonly used unit of metal material conductivity and resistivity

Conductivity -commonly used unit of metal material conductivity  and resistivity 

commonly used unit of metal material conductivity  and resistivity 

Volume resistivity :the conductor resistance of the unit length and unit sectional area,under the standard temperature of t0

P（t0）=·R（t0）

A（t0）--the sectional area of sample under standard temperature L（t0）--length of sample under the standard temperature 。  

Mass resistivity :the resistance of the conductor of unit length and unit mass ,under the temperature of  t0

δ（t0）=·

R(t0)--standard temperature is t0,the resistance of the  gauge length sample

M--the mass of sample  

L1（t0）--standard temperature is t0,the gauge length of the sample

L2（t0）--standard temperature is t0,the whole length of the sample

The resistance of unit length

R1（t0）=

R1（t0）--standard temperature is t0 ,the resistance of the unit length

R（t0）--standard temperature is t0,the resistance of the sample with gauge length 

L1（t0）--standard temperature ist0,the gauge length of the sample

The percent of IACS conductivity:the percent value of IACS volume conductivity or the percentvalue of  IACS mass conductivity。The value is the radio of resistivity and the resistivity of the same unit sample then multiply 100 according to international annealed copper standard.