A contactless method to measure the electrical conductivity

Using eddy current method, we developed a simple system to measure the electrical conductivity of material contactlessly. Three coils were used in this method. One coil was used to produce the excitation magnetic field. The other two coils were used to compose the differential detection coil to detect the magnetic field produced by the eddy current. Using this method, we evaluated the electrical conductivity of copper alloy specimens with different fatigue testing conditions and found that the electrical conductivity of copper alloy had some relation with the damage of copper alloy. In the future, we will also use this method to measure the conductivity of the graphene composite film on aluminum foil.