The systematic checking of wheel diameters is an important part
of wear control, but to make the control complete it is necessary
to measure the wheel profile, too. Wheel profile measuring provides
information on the wear rate along the whole transversal profile,
not only at the taping line point. This information includes the
calculation of flange height, flange thickness, qR-measure and
gives instructions regarding the truing.
Since a systematic wear control system is based on a continuous process of measuring, it is imperative that the recorded measuring results are stored in the way they can conveniently be observed and worked with at any moment later on.
A reliable way to measure wheel profiles is to do it with GoWheel wheel profile measuring device. It is quick and easy to use. The measuring unit is attached to the wheel inner side (reference plane) by help of permanent magnets hosted in the bracket of the unit.
The measuring unit consists of a few moving parts. All sensoring and electronic parts are digital, which means that all the data gathered are found from the very beginning in digital form and therefore this device does not suffer from any problems typical for the analog technique. The measuring result is transferred to the host PC immediately after the measurement has been completed. The proper measuring is effected manually by pushing the carriage over the wheel profile. The measuring takes about 5 seconds. The device measures the y-value at every 0.1 mm of x-value (i.e. 10 measurements per mm). 1360 points per one measurement are measured.
The measuring can be made at a depot, where you can measure the train bogie by bogie, wheelset by wheelset under the train. Or you can take the device to the marshalling-yard and measure the wheels of the whole train first on one side and return on the other side.
The measuring unit is controlled by a portable standard PC. The GoWheel program in the PC compares every measured point with the standard reference profile stored in the program and calculates the radial difference (dY) between this theoretical profile and the measured profile. It indicates the biggest dY and its situation on the profile, as well as the most common variables, flange height, flange thickness, qR, etc.
GoWheel stores the measured data on the hard disk in binary format for space reasons. These measured data can, however, be converted with the auxiliary program Gwtoss to ASCII-format. In this way it is possible to observe the measurements for example in programs like Excel or Quattro, or move them to any other program that accepts ASCII-format.
The program permits you to view earlier measurements, also in plotter or printer hard copies, in the same way you can examine them immediately after measuring, even in magnifications of 3, 4 or 10 times. The wear as function of time is presented in the wear history display.
The GoWheel program is able to calculate two kinds of turning instructions: those based on the biggest dY and optimized turning instructions, which mean adopting a thinned flange to minimize the loss of material.