I'm trying to measure the resistivity of a sample of A356 to back out the thermal conductivity. I do not have anything sensitive enough to measure the micro-ohm resistance (my sample is 0.5" x 0.25" x 3"). If I want to use an oscilloscope or multimeter to measure the voltage drop, I should need in the neighborhood of 1000A for a rough 10mV drop. Could I use a car battery to provide this colossal current? Thanks for any help.