ECC值的设定

The ECC value is input through a real constant, which can be a function of temperature [(Tt + Tc)/2], pressure, and time, by using the %TABLE% option. For the current conduction option, the electric contact conductance ECC has units of electric conductivity/length.
我是做电流传导分析的，上面提到的Lengh是什么意思？是单元的长度还是什么？？