The copper traces have a small but measureable resistance.  Try measuring a
voltage drop across them in circuit.  Watch out, cause if you change the plating
or copper thickness on the board, that resistance may change.  How accurate do
you need to be?

Chris Eddy

Gabriel Caffese wrote:

> Hello,
>
>         I need to know if a small current, that falls between 0.2ma and 3ma,
> flows over a pair of copper wires of printed circuit boards.