Report on APMP supplementary comparison: high precision roundness measurement

Abstract

A regional supplementary comparison, APMP.L-S4, was held in 2012 to demonstrate the equivalence of routine calibration services offered by NMIs to clients. Participants in this APMP.L-S4 comparison agreed to apply multi-step method for spidle error separation in order to yield the high precision roundness measurement. Eight laboratories from NMIs participated in this supplementary comparison; NIMT, NMIJ, NMIA, NIM, CMS/ITRI, KRISS, NMC/A*STAR and NMISA. This report describes the measurement results of 2 glass hemispheres and 2 softgauges. The calibrations of this comparison were carried out by participants during the period from March 2012 to May 2013. The results show that there is a degree of equivalence within 0.8 for all measurands. Hence, there is a close agreement between the measurements. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A cylindricity evaluation approach with multi-systematic error for large rotating components

“…Based on the above-mentioned cylindricity measuring instruments, numerous scholars have proposed a number of measurement models to reduce the cylindricity evaluation uncertainty [16][17][18][19]. The eccentricity error caused by misalignment between the geometric axis and turntable rotating axis is considered in the Limacon circular profile measurement model, which effectively reduces roundness evaluation uncertainty [20,21]. Compared with the roundness measurement, the eccentricity error of the measured section is caused by two parameters in the cylindricity measurement [22,23].…”