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Figure 6-2. Area identification for defect analysis. A) Properly defined defect area. B)
Poorly defined defect area. C) Surface plot of properly defined area. D)
Surface plot of poorly defined area
Once this area was defined for each defect, the next step was to compute the
parameters shown in Table 6-2 at each time step in the series of thermal images.
Table 6-2. Parameters computed for defect area at each time step
Parameter Description
Tmax Maximum temperature bounded by the area
Tper avg Average temperature along the perimeter of the area
Tper max Maximum temperature on the perimeter
Gper Standard deviation of the temperature values on the perimeter
ATdef is computed at each time step using the following equation:
ATdef= Tmax Tper avg (6-1)
Figure 6-3A provides a plot of Tmax and Tper avg vs. time for the defect highlighted
in Figure 6-2A. The corresponding ATdef VS. time plot is provided in Figure 6-3B. Once
this ATdef vs. time plot has been generated, the next step is to extract additional
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