Process for testing the purity of the constituent material of an electrically conducting item

摘要

The invention relates to the research and analysis of materials using electrical systems. It constitutes a test of the inhomogeneity of an electrically conducting item by examination of the thickness of the constituent material of said item. For example, the invention can be used to check for possible facsimiles of items in the form of precious or rare metal ingots. The process consists in sending an alternating current within a given frequency range through the item; for every frequency value of the current, the tension or strength of the current on the portion of the item being tested is measured. During the processing of the measured signal, its value is compared with that of a reference signal of the same frequency which is provided from a bank of previously obtained signal values corresponding to the predetermined standard dimensions of an item. If there is a discrepancy between the compared values, the discontinuity in the homogeneity of the material is established. The value of the resistive characteristic is measured in the form of the resistance or specific resistance of each layer of the material situated at a depth corresponding to the values of two adjacent frequencies in a given range, thereby enabling the discontinuity in the material's homogeneity with respect to the thickness of the item to be determined.