BS EN 16729-3:2018 pdf free.Railway applications – Infrastructure – Non-destructive testing on rails in track Requirements for identifying internal and surface rail defects.
BS EN 16729-3 There is no single, universally applicable inspection method – all have advantages and disadvantages.lt is therefore recommended that inspection systems be chosen and combined in order to ensure thatcertain defect types do not remain undetected.
Each NDT method focuses on a specific area of the rail cross section and defect type.
Transverse plane, vertical plane and horizontal plane are defined according to Figure 4.5.3 Visual testing – VT
Visual testing of rails is a direct visual examination of the condition of a section of rail,specifically thesurface of the rail head, to detect the presence of a defect, define and measure it.
Visual Testing can be divided into two categories:
– general visual testing; – detailed visual testing.
General visual testing (for example walking the track) is used for detecting the presence of defects. Inthis case, the rail shall be illuminated, if necessary, with auxiliary lighting to attain a minimum of 160 lxand the distance between the viewing position and the rail surface may be more than 600 mm.
Detailed visual testing is used for defining and measuring defects (for example the assessment of RCF).ln this case, if necessary, the rail shall be illuminated with auxiliary lighting to attain a minimum of 500lx.The distance between the viewing position and the rail surface shall not be more than 600 mm with aviewing angle of not less than 30° from the rail surface.
Consideration shall be given to the application of illumination to maximize the effectiveness ofthe test by:
– using the optimum direction of light with respect to the viewing point;-avoiding glare;
-optimizing the colour temperature of the light source;
-using an illumination level compatible with the surface reflectivity.
Visual testing is capable of inspecting the head, web and the upper surface of the rail foot for surface-breaking defects and damage.BS EN 16729-3 pdf download.