Nondestructive Testing of the Physicomechanical Properties of Zinc-Oxide Varistors Proposed by Different Manufacturers

Resumo

We present the results of investigations by the nondestructive acoustic methods of the physicomechanical properties of zinc-oxide ceramic varistors produced by the leading foreign firms, such as ABB and Epcos, and the St.-Petersburg Plant of Energy-Protective Devices. We describe and discuss the results of application of this method for the determination of the properties of disk-shaped varistors with various diameter-to-height ratios. Note the range of particle dimensions of the powders used for the formation of varistors affects their physicomechanical properties.