scope:

The Physikalisch-Technische Bundesanstalt (PTB) has developed a novel internal involute microgear measurement standard for research and industry. In this work, we present a comparison between the tactile calibration performed using our micro coordinate measuring machine (μCMM) and the measurement results obtained by means of our computed tomography (CT) system, our optical CMMs, and our gear measuring instrument (GMI). Profile and helix deviations provide the basis for this analysis. CT and optical methods make it possible to obtain a three-dimensional reconstruction of the workpiece; this reconstruction can be useful for aerial evaluation techniques and reverse engineering. However, research on the traceability and reliable estimation of measurement uncertainties is still ongoing.

In this paper, we compared the new results of the comparison measurements with the results of the comparison measurements of our external microgear measurement standard. This measurement standard was also calibrated and measured by means of tactile, optical, tactile-optical and CT systems. The results indicated good agreement between the measuring machines. Both microgear standards feature 16 teeth with normal modules of 1 mm, 0.5 mm, 0.2 mm, and 0.1 mm. The measurement standards are made of titanium to be compatible with the CT system; a second version is made of carbide. The tip diameter is 20 mm, which facilitates handling despite the embodied microgeometries. The results and discussion provide an overview of the state of the art in microgear metrology.