Preliminary Uncertainty Estimation of the Pressure Distortion Coefficient of a Pressure Balance by FEM Calculations

摘要

The great development of the Finite Element, the Volume Element and the Boundary Element Methods allows the solution of metrological problems with estimated uncertainties that are improving as far as experience is reached and methods are validated by experimental results. Consequently the uncertainty estimation in the numerical Finite Element Method is still an open object of debate. In the present work an iterative method based on Finite Element Method, developed by the IMGC-CNR in Turin and the University of Cassino, is applied to characterize the national primary standard for liquids from 10 MPa to 100 MPa (IMGC-100-NN_(tc)). Particular attention is paid to the evaluation of the different contributions to the uncertainties in the calculation of the pressure distortion coefficient of the piston-cylinder unit.