Skip to main content
Article thumbnail
Location of Repository

The geometrical interaction of the stylus and the measured surface in 3D roughness measurements

By Helmy A. M. Dowidar


The target of this work is to study the effect of the stylus tip geometry on the\ud surface roughness measurements by the stylus methods. A computer simulation\ud of the measuring process in 3D using arbitrary tip shapes has been undertaken. A\ud novel feature of this simulation is that it determines and reports the contact\ud distribution of the contact points on the stylus when scanning each surface.\ud Following analysis of fully simulated data to establish the fidelity of the simulation\ud process, it was applied to data set from real surfaces. First these were examined\ud using ideal (sometimes truncated) pyramid, conical and spherical tips. Then tip\ud shapes determined from the measurement of real styli were used. Relatively large\ud tips (of the order of 10 μm) were used in order to ease the need for measurement\ud resolution. The simulation results were evaluated against real measurements of\ud the surfaces. A bespoke measuring system was developed for this, adding X-Y\ud scanning and a means of interchanging styli while maintaining micrometer lateral\ud positioning between measurements. The shape of each stylus tip has been\ud determined using a technique based on the replication by indentation into a soft\ud substrate (typically lead).\ud The roughness values of the real surfaces when scanned (theoretically) by the real\ud tips have been compared to the roughness values of the same surfaces when\ud measured by the measuring system with different tips. This comparison has shown\ud a good compliance of both the theoretical and the practical results. This provides a\ud degree of confidence for interpreting details of the simulation as having practical\ud relevance.\ud Both computer simulation and real measurements confirm the trends that would be\ud expected from earlier studies. For example, amplitude parameters tend to drop in\ud value as stylus size increases. The distribution of stylus contacts in simulation\ud suggests that it is rarely to be found near the nominal centre of the tip. It is also\ud clearly demonstrated that real worn tips do not necessary act as if blunt, contacts\ud concentration in small regions when local features dominate. These results have\ud significant implementations for the uncertainty in topographic measurements

Topics: TA
OAI identifier:

Suggested articles


  1. (Meiji Univ); Naoi, Kazuya; Tsukada, Tadao , "Software-based relocation technique for surface asperity profiles and its application to calculate volume changes in running-in wear", doi
  2. 3-D surface topography measurement system and its applications", doi
  3. A controlled-force stylus displacement probe", doi
  4. Accuracy of replica materials when measuring engineering surfaces", doi
  5. Analysis of surface profiles by computational methods",
  6. Assessing the effect of stylus tip radius and flight on surface topography measurements", doi
  7. (1988). Assessment of surface roughness", Parts 1, British Standards Institution,
  8. Comparison of surface roughness measurements by stylus profiler, AFM and non-contact optical profiler", doi
  9. (1994). Comprehensive study of parameters for characterizing 3-D surface topography? III: Parameters for characterizing amplitude and some functional properties. Wear doi
  10. (1978). Computer assistance in surface topographic analysis",
  11. Dependence of measuring errors of rms roughness on stylus tip size for mechanical profilers", doi
  12. Design and performance assessment of a Kelvin clamp for use in relocation analysis of surface topography", doi
  13. Digitization of surface profiles", doi
  14. Dynamics and trackability of stylus systems", doi
  15. Effect of noise on surface roughness measurements", doi
  16. (1970). Effect of stylus radius on the roughness values measured with tracing stylus instruments", doi
  17. Effects of finite stylus width in surface-contact profilometry", doi
  18. Effects of the non-vanishing tip size in mechanical profile measurements",
  19. Frictional forces between a diamond stylus and specimens at low load", doi
  20. (1994). Handbook of surface metrology",
  21. Importance of checking the stylus radius in the measurement of surface roughness", doi
  22. Measurements of stylus radii", doi
  23. (2001). Metrology and properties of engineering surfaces", doi
  24. Problems in surface metrology", doi
  25. (1997). Product Specifications (GPS) . Surface Texture: doi
  26. Replica techniques for the study of fracture surfaces and topography study in general",
  27. (1999). Rough Surfaces",
  28. Selection of an enveloping circle radius for E-system roughness measurement", doi
  29. Software relocation of 3D surface topography measurements", doi
  30. Some effects of stylus force on scratching surfaces", doi
  31. Spectral analysis for the effect of stylus tip curvature on measuring rough profiles", doi
  32. Spectral analysis for the effects of stylus tip curvature on measuring isotropic rough surfaces", doi
  33. Stylus / computer system describing three-dimensional engineering surfaces", doi
  34. Stylus flight in surface profiling", doi
  35. Stylus profiling at high-resolution and low force", doi
  36. Suitability of the envelope line as a reference standard for measuring roughness",
  37. Surface metrology", doi
  38. Surface topography as a nonsatisfactory random process",
  39. (2002). Surfaces and their measurement", doi
  40. The 3-D assessment of surface roughness and its implement with MATLAB",
  41. Three-Dimensional measuring technique for surface asperities", doi
  42. Three-Dimensional relocation profilometer stage", doi
  43. Toebben, Helmut; Schmitt, Dirk-Roger, "Comparison of a simulation model investigating the scanning of surfaces by mechanical profiling systems with current measurements", doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.