Thermal Sources of Errors in Surface Texture Imaging

Abstract

This paper presents the influence of thermal phenomena on areal measurements of surface topography using contact profilometers. The research concerned measurements under controlled and variable environmental conditions. The influence of internal heat sources from profilometer drives and their electronic components was analyzed. For this purpose, a thermal chamber was designed and built. Its task was to maintain and control environmental conditions and, at the same time, separate the profilometer from external disturbances. Heat sources and temperature values for elements and systems were determined. It further enabled for the calculation of the displacements in axes as a function of temperature. The largest displacement in the probe due to internal heat sources for the considered cases occurred in the X-axis direction. Its value reached 16.2 μm. However, the displacement in the probe in the Z-axis direction had the greatest impact on the measured surface topography. These displacements for a thermally unstable profilometer reached 7.9 μm in Z, causing results even 90% greater than in the case of a device without such problems. The time after which a proper topography measurement can be started was also determined basing on obtained data. This time for tested profilometers was between 6 and 12 h. It was found that performing thermal stabilization of the profilometer significantly reduced surface irregularity errors. The stabilization time should be determined individually for a specific type of device.

Surface Texture Measurement on Complex Geometry Using Dual-Scan Positioning Strategy

“…Experiments were conducted to verify the measurement performance of the proposed dual-scan scanning method. Because temperature-induced deformation of the measurement modules may affect measurement accuracy [28], the measurement tests were performed in an air-conditioned workshop, with temperature controlled at 20 ± 2 • C. The reference systems were also working in a laboratory with the temperature controlled at 20 ± 1 • C. In order to minimize the influence of temperature variation, the data capture processes were completed within 3 min.…”

The Effects of Selected Measurement Errors on Surface Texture Parameters

“…High-frequency noise can also cause errors of surface topography measurement using optical and tactile methods [ 17 ]. Some errors are also related to temperature issues [ 18 ].…”

Reduction of Influence of the High-Frequency Noise on the Results of Surface Topography Measurements

“…Furthermore, the noise has different sources, including those internally generated and external sources from the environment [ 12 ]. It was also assumed that profilometer after thermal stabilization shows 90% less noise than in the case of an unstable profilometer when thermal sources of errors in surface texture imaging were considered [ 13 ]. Evaluation of every single contributor is not always achievable for some instruments.…”