DMA specializes on the design and manufacture of instruments for measuring tracks and train’s wheels and in the development of software to compute wheel-rail interface parameters. DMA has a long experience in the measurements on tracks and trains. In DMA, engineers specialized in the instrumentation design work together with engineers specialized in the railway engineering. The experience in both the application and the technology is a key issue for developing the best products.

This document describes the non-contact rail profile measurement device dedicated to the evaluation of the rail wear and of the equivalent conicity according to UIC519. It’s a powerful tool for investigating the train running dynamics.

The instrument is based on laser triangulation technology. This is not a new technology in railway application, but DMA was the first Company that applied this technology to the railway engineering and running dynamics necessities.

The internal solutions has been chosen and tested to reach a high level of accuracy able to solve all the problems of the running dynamics of high-speed trains.

The following pictures show the instrument in two different mechanical editions, suitable for the installation on different bogies (each one is the best depends on the particular bogie and the room available).

Fig. 1: Tthe instrument mounted on a passenger coach bogie

Fig. 2: This version of the instrument is mounted on a high speed tilting train bogie

In both editions the two lateral boxes are the instruments measuring the rail profile. An inertial system for track geometry measurement can be easily added in the middle, as a separate box mounted on the same rigid rod (as in the first picture: this edition is easier to assemble/disassemble), or in a central structure connecting the two instruments (as in the second picture: this edition is more compact). The instruments are installed on a single rigid rod, mounted on a bogie. A number of cables connect these instruments to the electronics racks, mounted in the car body (a compact 19” rack, 18 U high). Videos and printers are installed according to the requirements for the real time display and printing of data. The system is so compact and easy and quick to install that it can also be mounted on trains in regular revenue service. No moving parts or mechanical transducers insure high reliability and long life. The instrument measures the rail profiles and track gauge. The rail wear is computed by reference to a sample profile, or to previous measurement. The equivalent conicity is computed as well, thanks to the high accuracy of the instrument.