STATISTICAL DETERMINATION OF LIFE EXPECTANCY, DEFECT AND FAILURE RATES FROM ACCELERATED ENDURANCE TESTS ON RELAYS

摘要

Electromechanical relays, while subject to increasing miniaturization, are required to provide ever greater reliability. This requires new production technologies and development methods. As well as improved methods in the design of these components, materials selection must be based on the latest available knowledge. This knowledge can only be derived from statistically based life expectancy and reliability data. Users and manufacturers have been performing life expectancy and reliability tests on relays for a long time and standards on statistical analysis have been established. This paper reports on investigations using failure and defect rates from endurance tests as a criterion for the reliability of relays. As a result of monitoring leakage current and voltage drop at all contacts under load during each cycle, data is obtained from which it is possible to determine the lifetime statistically from the Weibull distribution of observed defects.