The key issue here is that, although the absolute magnitude of discharge events cannot
be determined from this technique, knowing the location of the source may be just as,
if not more, important. For example, a source identified as coming from a winding
might give serious cause for concern whereas, if the source is corona from a core
bolt, it might not. Asource within the winding will erode the paper and could lead to
a catastrophic failure in time.Acore bolt suffering corona will result in change to the
dissolved gas levels but will not age the transformer in any significant way.