Downloaded from https://www.everyspec.com F4 AMOP M106. Example No. 35 A newly designed motor-generator set must be tested. Suppose that under severe conditions of teipperature, humidity, and load, that the rate of degradation is 90 times as b4 as under odinary opnditions; Lse., the time acceleration factor is 90. Tea, items are put on test; the first 2 failures are at 26.7 hr and 43.2 hr, respectively. Estimate the actual Cdf/ Procedure S R 1. Use the Kolmogorov s- 1. Acceleration factor - 90, ounfidenoe limits in par. 2-o, Caiouaate *"90 x 26.7 hr a 2403 hr the timas-to-lailurs s 90 x 43.2 hr w 3888 hr. under usual conditions. 2, Find the 90% x-confi- 2. d * 0,37 for 90% s-confidenoe.
denoe d from Table 2-12, 3. Use Eq. 2*48 to oal- 3, a. For i - 1: Fis - 1/10 - 0.10, FLO 0/10 - 0.00; Oulate the envelope for thus for 0 S t S ti, the upper limit for the Cdf the Cdf where i - fail- is 0. 10 + 0, 87 47%, and the lower limit iso 0. ur'e number and N- sample size. b. For i w 2. Fl -2/10 - 0.20, FL. - 1/10 - 0.10; samplesize.thus for tj t 9 t2, the upper limit for the Cdf it 0.20 + 0.37 - 57%, and the lower limit is still 0. As with .ll tests involving only a few specimens, the results are discouragingly imprecise. . "%AN" .......... . . .. .. .