The first trial section of track examined with the rail inspection train (Fig. 12) had the aim of comparing the results received with different scanning speeds to the results from manual inspection in order to estimate the accuracy of the inspection system. In Fig. 12 results are presented which were recorded at different scanning speeds. By this original data are the vertical axis the amplitude of the received eddy current signal. It is apparent that there is an extraordinarily high-degree of reproducibility, which demonstrates the reliability and accuracy of the eddy-current measuring system used. It is also noticeable that head checks are still present in the reground section of rail. This indicates an important area of application for eddy-current testing: assessing the quality of regrinding work by checking whether the re-profiling operations have indeed been successful in removing all the head checks. A further example is shown in Fig. 13 in which the results of the manual Fig. 13. Measured data different scanning speeds. inspection are compared with those of the inspection train. For this particular case the train speed was 76 km/h. The results compare well.