Calculation of effective area A0 for six piston–cylinder assemblies of pressure balances. Results of the EUROMET Project 740

Six European metrological institutes compared their calculation methods, and estimated uncertainties, resulting in the derivation of the effective area A0(20 °C, patm) of six piston–cylinder assemblies routinely in use in pressure balances that are primary standards of the pressure laboratories, operating in different pressure ranges in gas (up to 1 MPa) and in liquid (up to 1 GPa). The results for A0 and its standard uncertainty u(A0) are presented and compared.