Tracking Resistance Erosion Test Equipment is used for checking the relative behavior of solid electrical insulating material with regard to their susceptibility to surface tracking when exposed under electric stresses, to water and contaminants, from the surroundings.
The grading of materials arrived at by checking the tracking index may possibly differ from that obtained by utilizing other checking methods for the measurements of the tracking index.
The results obtained by checking tracking index are not used directly for evaluation of safe creepage distances while designing any electrical apparatus.
With this apparatus drops of an electrolyte are dropped at defined time interval to the surface of insulating materials between two electrodes to which a voltage is applied.
The number of drops at which break down occurs across the surface is the function of voltage
The numerical values of the voltage corresponding to the asymptotes defines the tracking resistance.The value of voltage corresponding to number of drops is taken as the comparative index. (This test should be done as fast as possible)
The number of drops to cause tracking at value of predetermined test voltage 10% below the number of drops value is indicated as the degree to which the reported comparative tracking