An instrumentation system for evaluation of contact materials

Abstract

The quality of contact materials depends on their physical properties (such as density, hardness and conductivity) as well as on their contact characteristics. The latter contribute critically to the reliability of these materials and include parameters such as contact resistance, weldability and erosion. An instrumentation system is described here which measures the most important attributes of contact materials simultaneously. The important measurements are taken under simulated service conditions. The rated electrical current is passed through contacts of reference and test materials in a contactor controlled by an electronic module; the contact resistance, weldability and arc erosion are monitored. The instrumentation system has been successfully used to rate various contact materials in a reliable and reproducible manner. The instrumentation scheme, measurement techniques and test results are described.