The Effect of Height on the Current Distribution Measured with a Vibrating Electrode Probe

The vibrating electrode probe technique for measuring local currents has been tested in order to determine its spacial resolution and to develop methods for analyzing experimental data. Measurements were made with a current source of known size in an insulating plane. Results from this model have been compared with analytical solutions taken from the literature and computer simulations. When the probe was less than 0.2 times the radius of a current source, the major field variations were above the periphery of the source. For heights greater than the diameter of the current source, the field variations closely approximated those of a point current source because of the rapid spreading of the current in the solution. This characteristic was used to simulate the field variations above electrodes by replacing electrodes with an array of elements, each having a single point current source.