Oil breakdown voltage. An insulating oil was tested between a pair of parallel disk electrodes under a voltage that increased linearly with time. The oil breakdown voltage was measured 60 times each, with two sizes of electrodes. According to theory, a pair of 3-in.-diameter electrodes act like a series system of nine independent pairs of 1 -in.-diameter electrodes. The following analyses check this.
(a) Make a Weibull hazard plot of the voltage data from the I-in.- diameter electrodes
(b) Carry out the hazard calculations for the data from the 3-in.- diameter electrodes, treating each failure as the first among nine 1-in. electrodes. The eight survivor times immediately follow their corresponding failure time.
(c) Plot the results of (b) on the paper with the 1-in. data.
(d) Are the two sets of data comparable?