Electromagnetic testing emt-mft chapter 9b

2.3 Analysis of Leakage Field Data.
In most applications of the leakage field method, there is a need not only to
detect the presence of a flaw but also to estimate its severity. This leads to
the problem of flaw characterization, that is, the determination of flaw
dimensions from an analysis of leakage field data. The most widely used
method of flaw characterization is based on the assumptions that the leakage
field signal amplitude is proportional to the size of the flaw (which usually
means its depth into the material) and that the signal amplitude can therefore
be taken as a direct measure of flaw severity. In situations where all flaws
have approximately the same shape and where calibration experiments show
that the signal amplitude is indeed proportional to the size parameter of
concern, this empirical method of sizing works quite well.
Keywords:
The most widely used method of flaw characterization is based on the
assumptions that the leakage field signal amplitude is proportional to the size
of the flaw (which usually means its depth into the material) ()
Charlie Chong/ Fion Zhang