The paper reports about the building up a computer controlled measurement system based on National Instruments Data Acquisition card and National Instruments LabVIEW software package. The aim of this research is to detect manufactured surface cracks on steels by applying a magnetic flux leakage testing method. First of all, a finite element method based on the procedure to analyze the behavior has been implemented of the measurement system under construction. One important question is the position of the sensors or of the detecting coils. The finite element procedure contains a two dimensional arrangement. First, eddy currents have been neglected, but the nonlinear characteristic of the specimen has been taken into account by a single valued function. In this paper, the developed measurement system, which is partially ready to work, and the nonlinear finite element procedures are presented as well. © 2008 Akadémiai Kiadó.