Three methods were used for measuring the radii of the same stylus of our stylus instrument. The measurement results were compared and showed good agreement. Using razor blade tracing, the stylus radius was measured as r=1.60um with an expanded uncertainty k=2) of 0.16um. Using a pair of optically matched convex and concave lenses with the same radius, the stylus radius was measured as r=1.52um with an expanded uncertainty (k=2) of 0.18um. Using a standard wire and two ruby balls whose diameters were calibrated at the NIST dimensional metrology laboratory, the stylus radii were measured as r=(1.70 +/-0.08)um, (1.67 +/-0.12)um and (1.74 +/-0.05)um (all with k>=2) corresponding to different daily calibrations. From the latter measurements, we obtained a value for the stylus radius and estimated its measurement uncertainty. By using the stylus radius to correct the measurements of our stylus instrument, we have calibrated the least squares radii of Rockwell hardness diamond indenters with an expanded measurement uncertainty of less than 0.3um.
Proceedings of 1997 International Conference on Precision Engineering (ICPE 97, Taipei)
January 1, 1997
1997 International Conference on Precision Engineering (ICPE 97, Taipei)