Final report on comparison EURAMET.M.P-S6 of PTB and INTI pressure standards for the range 1.5 kPa to 300 kPa of absolute gas pressure

Abstract

This report presents results of a bilateral comparison between PTB and INTI in the range 1.5 kPa to 300 kPa of absolute gas pressure. The comparison was carried out in April–May 2008. The pilot laboratory was PTB. The pressure standards of the participants were pressure balances of the same type. The transfer standard was an electronic pressure gauge. Deviations of the transfer standard's pressures from the reference pressures generated by the laboratories' standards at specified pressures were reported by the participants and used for calculating degrees of equivalence between the laboratories. The results of the comparison presented in the Draft A report have induced INTI to revise their uncertainty by an increase in the uncertainty of the residual pressure. After this revision, the results presented in the actual report demonstrate equivalence within the expanded uncertainties (k = 2) reported by the laboratories at all pressures of the comparison. The degrees of equivalence stated in this comparison will provide a supporting basis for a new pressure CMC table of INTI.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 EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Dielectric-constant gas thermometry

“…For the second goal, it was necessary to characterise pressure balances with an unprecedented quality and even to improve the national standard of PTB significantly. A system of special pressure balances, as outlined in [28,29], was designed, constructed and evaluated [30][31][32][33], see also the summary in [5]. The system includes two pressure-balance platforms, three piston-cylinder units (PCUs) with effective areas of 20 cm 2 and three 2 cm 2 PCUs.…”

“…He eff (28) where the indices He and Ne denote the specific quantities. Due to the very small polarizability of 4 He, the experimental application of equation ( 28) places, however, extreme demands on the equipment used for measuring p, T, and μ.…”