Final report on supplementary comparison APMP.M.P-S8 in hydraulic gauge pressure from 100 MPa to 1000 MPa

Abstract

This report describes the results of a supplementary comparison of hydraulic high-pressure standards at two national metrology institutes (NMIs) – National Metrology Institute of Japan, AIST (NMIJ/AIST) and Physikalisch-Technische Bundesanstalt (PTB), Germany – which was carried out during the period January 2007 to March 2007 within the framework of the Asia-Pacific Metrology Programme (APMP) and the European Association of National Metrology Institutes (EURAMET) in order to determine their degrees of equivalence at pressures in the range 100 MPa to 1000 MPa for gauge mode.The pilot institute was NMIJ/AIST. NMIJ/AIST used a hydraulic pressure balance and a pressure multiplier, and PTB used a controlled-clearance pressure balance as their pressure standards. High-precision pressure transducers were used as a transfer standard. The sensing element of the transducers was a foil strain gauge. To ensure the reliability of the transfer standard, two pressure transducers were used on the transfer standard unit. At the beginning and the end of this comparison, the transfer standard was calibrated at the pilot institute.From the calibration results, the behaviour of the transfer standard during the comparison period was characterized and it was found that the capability of the transfer standard for the purpose of this supplementary comparison was sufficient. The degrees of equivalence of the national measurement standards were expressed in terms of deviations from the supplementary comparison reference values and from each other, considered in combination with associated uncertainties of these deviations. The hydraulic pressure standards in the range 100 MPa to 1000 MPa for gauge mode of the two participating NMIs were found to be equivalent within their claimed uncertainties.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 APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).