User's Manual

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Center Correction explained in detail 7.2
With correlation we measure the time delay between the leak noise reaching both sensors:
Figure 77: Center Correlation
From this we can calculate the leak distance from both sensors, but only if we know the pipe
length between the sensors x. In practice, in ZONESCAN NET we often don’t know the pipe
length because it was not entered using the pipe wizard of manual pipe entry.
Even if we don’t know the pipe length however, we can always calculate the offset of the leak
from the center between the sensors using the default sound velocity. This is called center
distance.