If I understand your question correctly, the clear choice is a Ohm meter which is part of every handheld and rack mounted multimeter. 

Following thorough answer of Martin Stutzmann, one can add the necessity of tight junction of sample ends with contacts of probe setup. Owing to high conductivity of copper, quality of junction essentially determines the error of measuring. 

tobstart just get multimeter and measure the resistance of the copper wire

According to Mohamad, just take a long piece of wire just enought to  distinguish the reading and take also variations of temperature into account.