Comparison of the national pressure standards of the Russian Federation (VNIIM), Germany (PTB) and Slovakia (SMU) in the pressure range 1 MPa to 3 MPa (COOMET project 115/RU/95)

A comparison between the D. I. Mendeleyev Institute for Metrology (VNIIM, Russian Federation), the Physikalisch-Technische Bundesanstalt (PTB, Germany) and the Slovak Institute of Metrology (SMU, Slovakia) was organized by the VNIIM as the coordinator and pilot laboratory of a COOMET project that started in 1995 and finished in 1998. The comparison was realized on the basis of cross-float experiments with two transfer standards - 5 cm2 piston-cylinder assemblies for pressure balances - manufactured by, and belonging to, the VNIIM. The transfer standards and the methods applied to determine their effective areas, A0, are described and comparison results presented. With the equivalence criterion for the agreement between any two participants taken to be |A0i - A0j|/A0 = 2[ui2 + uj2]1/2 (u being the standard uncertainty of the effective area of the transfer standard used), the national standards of the participants for the pressure range covered by the comparison experiments may be considered to be equivalent. As one of the participants in the present comparison (PTB) used the same primary standards in comparisons organized by EUROMET and by the Consultative Committee for Mass and Related Quantities (CCM), the participants in this COOMET project can indirectly compare their pressure standards with those of other European countries, Japan, and the United States.