Laser-BasedCross Sections Meter


Contour is a laser based device for the measurement of cross sections of tramway and flange rails, cross sections of frogs including their grooves. Contour operates on the triangulation principle of flat sampling of the entire laser path on the surface of the measured rail. Cross section illuminated by laser beam in form of light path is sampled at one moment. The red laser with cylindrical lens is used in order to generate the laser path. To sample laser mark image on the rail surface, area image sensor with integrated control computer is used.

The applied triangulation principle of the entire flat sampling shows the following advantages :

  • high speed of measurement, approx. one hundred cross section per second
  • easy and safe measurement on track under operation, nothing has to be fixed on rail which anytime may be quickly escaped from,
  • the measurement of the entire cross section is performed during a few milliseconds, a possibility of the measurement quality affecting by operating personnel´s error is reduced.

Contour allows to measure of the following parameters :

  • tramway rail head section and groove shape,
  • the relative vertical position of the rail head referred to the surrounding surface of the concrete road
  • tramway rail frog section and crossing section,
  • tramway rail switch tongue section,
  • flange rail switch frog section,
  • flange rail switch tongue section,

Contour is a manually operated battery- powered apparatus. It consists of measuring laser head with measuring electronics and internal computer, and a trolley for continuous measurement on a track. Laser head contains all electronics required to sample image and transfer it to the internal computer and realtime visualisation during measurement. Laser head together with a set of distance legs may be applied as stand-alone apparatus for the measurement of individual cross sections. Laser head in conjunction with the trolley allows to perform a continuous measurement of frog sections directly in railway track and conduct continuous measurement of the entire switch section (tongue and frog area).

The measured data are permanently stored in the internal computer. Operator in real time sees the individual measured cross sections and also may, during the measurement, compare them with earlier measured courses or courses set by standard.

Measurement of individual cross sections

To measure the individual sections, laser head with a set of exchangeable legs and control computer are sufficient. Supporting legs adequate to the type of measured rail are put on laser head. These supporting legs are of various types depending on the place of measurement (for frogs, for flange rails and for tramway rails). Shape of their ends is adapted to the type of measured rail. By simple putting the cross section meter´s supporting legs on a rail, one cross section, without the necessity of additional adjustment, is measured. For the measurement of tramway rails, one cross section for the entire rail shape is sufficient.

Measurement of a group of selected cross sections in production process

Laser head, single-rail trolley and control computer are required to conduct the measurement of cross sections in production process. Single-rail trolley is put on the measured frog and laser head is fixed onto trolley. Trolley travels to the frog beginning and operator starts the measurement. Trolley is fitted with the position measurement. Trolley position is continuously transmitted to control computer and imaged on display. Operating personnel follows trolley position and according to it then by simply pressing the button on control computer measures the respective cross sections.

Continuous measurement of cross sections on track in regular intervals

Laser head, single-rail trolley complemented by supporting arm and control computer are required to conduct the measurement of cross sections on railway track. Trolley is assembled and put on track, with laser head fixed onto trolley. Trolley travels to the switch beginning and operator starts the measurement. Similarly to the previous case, trolley measures its position, transmits it to control computer and operating personnel according to trolley position measures the blocks of cross sections. The measurement on track can be divided into several separate blocks. It is therefore possible to separately save blocks of switch tongue cross sections, blocks of frog cross sections, etc.

Contour operates with user’s evaluation software. The software compares the measured cross sections with selected standardized shape of rail cross section. In defined points, the software reads and computes the differences between the measured and comparative cross sections. The measured data are stored in a standard format to allow easy data import to a firm’s database.

For evaluation, it is also possible to supply user software for PC which allows rotation, shifting, comparing and reading values of the selected points in cross sections.

The final version of user’s software is always adapted to the client’s requirements. Therefore, software supply always includes also the design of user’s interface and particular software functions exactly to match the final user’s order including the program porting into arbitrary national environment.

Technical parameters :

  • Contour is characterized by the following technical parameters:
  • laser head weight 13kg
  • laser head with trolley weight 23 kg
  • transport wight 29 kg
  • transport size 800x600x400mm
  • mounting to rail none
  • measuring range 200×100 mm
  • cross section resolution 0.05 mm
  • measurement accuracy +/-0.2 mm
  • laser class 2M
  • power internal battery or power adapter