## 5 Conclusions  
Despite the ongoing dynamic development of non-contact methods, tactile surface roughness measurements are still widely used both in scientific research and in industrial practice. One of the fundamental parameters of tactile measurement is the tracing speed of the measuring tip on the measured surface. In the case of a too-high tracing speed, the tip may lose physical contact with the measured surface, which results in very significant measurement errors. Therefore, contact instrument operators usually use low tracing speeds. Unfortunately, this is not beneficial considering the requirements of contemporary manufacturing processes, where it is often necessary to shorten the measurement time. This is why, in tactile measurements, the tracing speed should be selected in such a way that, on the one hand, it allows reliable results to be obtained and, on the other hand, it does not cause the unnecessary prolongation of the measurement time. The papers published so far described the influence of the tracing speed only for one selected surface and for a small number of roughness parameters. Therefore, the authors of this article decided to conduct research that would describe the influence of the tracing speed for various surfaces and many different roughness parameters. The results presented in this article indicate that the influence of tracing speed on the measurement results of individual roughness parameters may differ significantly for surfaces of different natures. 1. Surfaces engineered via horizontal milling. For horizontally milled (HM) samples, it was found that the influence of the tracing speed on the obtained results is relatively small for most parameters, except for the R\(\Delta\)q and RSm. For the RSm parameter in the case of two standards, the error values of the parameter determination exceeded 2% for each speed higher than the reference speed. For the standard HM1.6, these values ranged from \(-3.1\%\) to \(-3.2\%\). On the other hand, for the standard HM 6.3, the percentage error ranged from 2.8 to 3%. For the last of the HM standards (HM 1.6), there was no significant influence of the sensor speed on the measurement results of the RSm parameter. In the case of HM standards, another parameter that has been shown to be extremely sensitive to changes in tracing speed is R\(\Delta\)q. For each of the measured samples, the error values of the R\(\Delta\)q parameter were extremely large. Values ranged from 0-1.9% to 191% for the HM 3.2 sample, from 8.3% to 325.6% for the HM 1.6 sample, and from 1.1% to 63.3% for the HM 6.3 sample. Other parameters turned out to be much less sensitive to changes in tracing speed. However, the results presented show that at the tracing speed of \(v=2\) mm/s, the percentage error value exceeds 2% for some parameters; in particular, the Rv parameter. 2. The surface engineered via vertical milling. In the case of this surface, it is noticeable that the parameter most sensitive to the change in tracing speed is R\(\Delta\)q. In this case, the value of the percentage error of the determination exceeded the assumed threshold of 2% at a tracing speed of 0.5 mm/s, while at \(v=2\) mm/s, the value of this error was as high as 89.5%. Other parameters turned out to be much less sensitive to the increase in tracing speed. However, it was shown that for the maximum speed of \(v=2\) mm/s, the error value exceeded the threshold of 2% for all parameters tested except Ra, Rq, and Rku. 3. The surface engineered via reaming. As in the case of the previous standard, the parameter most sensitive to the change in tracing speed for the surface engineered through reaming is R\(\Delta\)q. In the case of R\(\Delta\)q, the percentage error of the determination exceeded the assumed threshold of 2% at a speed of \(v=0.5\) mm/s, and at \(v=2\) mm/s, the error amounted to as much as 60.6%. Among the other parameters, the RSm parameter turned out to be the most sensitive to the increase in tracing speed.