Changes

The large quantity of data generated during the these tests can be only analyzed with computer based test systems. After all the relays failed, a failure statistic is calculated and the expected electrical life is calculated based on the specified switching and operating criteria. (<xr id="fig:Statistical evaluation of the electrical life of relays"/><!--(Fig. 13.7)-->) shows in form of a Weibull diagram the results of a relay life test for a sampling of switching relays under a resistive AC load with failures after the first and the 10^th occurrence analyzed. From such electrical life test tests it is also possible to statistically predict the failure rate of relays under certain specified load conditions.