RSG gauge - examples of weld and rail straightness measurement results

Measurement accuracy

Rail straightness gauge accuracy and repeatability is very high - and can be easily verified at any time by the user, by measuring the certified master piece delivered with the device. The repeatability test results were obtained for 7 measurements of the same master piece. They are shown in two drawings for each plane: running and side planes of the rail - one of them shows the measurement results overlayed onto the master piece profile, and the other uses the averaged profile from all 7 readings as a reference profile to show the differences of each profile from the averaged one.

Weld straightness

Measurement results are stored in the control system memory, processed immediately after the measurement, and shown on its graphical display. The measurement results stored in the memory can be downloaded to the PC computer for generating measurement reports and for analysis of rail waviness on lengths exceeding 1.2m.

Waviness:
plot of differences of the Basic profile and Trend values (see also rail waviness)
Trend:
it is the averaged plot in the -100 ÷ +100 mm window along the basic profile as the reference base
Basic profile:
1.2 m long profiles of the running or side weld planes, allowable deviations for the fault level are shown as dotted line
Straightness measurement results in numerical format
Numerical format of the weld measurement results for the running (vertical) plane: the maximum deviation value of the running profile of the rail was +0.52 mm, whereas the allowable deviation was 0.2 mm, and the emergency value was 0.4 mm, therefore a warning marker * was added to the right; its meaning is that the weld requires immediate correction.
The minimum deviation value for this surface was within specifications. Information about the side weld surface is displayed in a similar way, preceded by () markers if the track gauge is bigger due to the weld shape, or )( if it gets more narrow.

Dedicated MS Windows based software delivered with the gauge makes it possible to access the measurement data and visualise them in detail, as well as to generate the weld straightness measurement reports: Example 1 (PDF file - 19 KB), Example 2 (PDF file - 19 KB).

Rail waviness

The Rail Straightness Gauge can measure waviness (corrugation) of the rails. This task can be carried out for inspection lengths equal to 1.2 m and longer - in this case much longer rail sections can be measured and analysed. Measurement of rail waviness on longer lengths is done by repositioning the gauge by half of its body length after each measurement.

Waviness:
plot of differences of the Basic profile and Trend values this is the same plot as in case of weld straightness.
Waviness measurement results in numerical format:
The numbers displayed represent: A - wave amplitude, and λ - wave length, as they were detected on a 1.2 m long rail section.

All these measurements, taken as overlapping ones, can be merged together later by the dedicated MS Windows based software delivered with the gauge. Nevertheless, rail waviness measurement results for the 1.2 m long rail sections are available on site and may be displayed on the control unit, longer rail sections require processing on a PC. Moroever, this software is designed to give the operator access to the measurement data and to make it possible to visualise them in detail, as well as to generate the rail waviness measurement reports: Rail Waviness Measurement Report (PDF file - 28 KB), RSG versus surveying method (PDF file - 32 KB).