Report of pilot study CCM.P-P1 for international comparison of absolute pressure measurements in gas from 3 × 10^-9 Pa to 9 × 10^-4 Pa

Abstract

A bilateral comparison of absolute gas pressure measurements from 3 × 10-9 Pa to 9 × 10-4 Pa was performed between the National Metrology Institute of Japan (NMIJ) and Physikalisch-Technische Bundesanstalt (PTB). It is a pilot study CCM.P-P1 for the next international comparison in this pressure range to test the stability of ultrahigh vacuum gauges (UHV gauges) as transfer standards. Two spinning rotor gauges (SRGs), an axial-symmetric transmission gauge (ATG), and an extractor gauge (EXG) were used as transfer standards. The calibration ratio of one SRG was sufficiently stable, but the other was not. This result indicates that improvements in the transport mechanism for SRG are needed. The two ionization gauges ATG and EXG, on the other hand, were sufficiently stable. Provisional equivalence of the pressures realized by the primary standards at NMIJ and PTB was found.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 CCM-WGS.