Abstract
The eddy current testing is used for a testing of the steam generator tubes in pressurized water reactor nuclear power plants because of its high accuracy and high speed. It is important to judge shape of cracks from measured signals. We have developed a rotating type probe using an excitation coil that generates uniform eddy current distribution. Because the shape of excitation current source has no influence on detecting cracks, numerical analyses for this probe are handled simply by devising boundary condition. Aid of numerical analyses has enhanced the evaluation of complicated cracks.