Measurement of the spatio-temporal distribution of harmonic and transient eddy currents in a liquid metal

Harmonic and transient eddy currents in a liquid metal positioned above an excitation coil are determined by measuring the voltage drop in a simple potential probe. The resulting spatio-temporal eddy current field is compared with the corresponding analytical expressions for a conducting half-space. Further, a deformation of the eddy current distribution due to a non-conducting torus immersed into the liquid metal is measured and compared with numerical results. The method can be generalized to arbitrary geometries, and might help to validate numerical models for non-destructive testing and magnetic inductance tomography.