motivation behind performing this computation is that defects close to the surface will
correlate more rapidly than deeper defects. Consider the surface plots for Defect A50
(Specimen A-2) provided in Figure 6-62. The R computed at t = 13 sec was 73%. R
increases to 87% and 95% for t = 18 sec and t = 23 sec, respectively. R is plotted as a
function of time for this defect in Figure 6-63. As long as the defect area at t = 60 sec is
used as the reference matrix in Equation 5-11, the resulting R value for all areas will be 1
at t= 60.
So \ ,1 1 .
'- --I -n
A
't.-
10 1510
C D
Figure 6-62. Surface plots of Defect A50 (Specimen A-2). A) t = 13 sec. B) t = tT12.
C) t = 23 sec. D) t = 60 sec.
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