Problems and good practices of measuring the railway wheel rolling diameter

The article describes the results of research on the influence of the methods used to measure the rolling diameter of a railway wheel "D" and measuring instruments on the accuracy of the obtained results. The differences in the results obtained using five different measuring instruments are presented. In particular, the difficulty of meeting the repair criterion |D-D'| was pointed out using the current measurement method. The article also illustrates the original measurement method proposed by author, which is a reference measurement for currently used methods, along with its limitations.