Effectiveness of finite element calculation methods (FEM) on high performance pressure balances in liquid media up to 200 MPa

摘要

In the framework of a bilateral cooperation between the I.N.RI.M./University of Cassino and DH Instruments, the authors tested the effectiveness of finite element methods (FEM) in predicting the behaviour of high performance pressure balances that are used extensively in national metrology laboratories and industry. The pressure balances under investigation operate up to 200 MPa (free deformation and controlled clearance types). The results of FEM calculations are presented, giving information on the baseline models adopted. All FEM numerical results are discussed and compared with the typical characteristics of the piston-cylinders observed in the metrology laboratory of the pressure balance manufacturer. Conclusions are drawn in terms of reliability of results based on an estimation of the parameters that have the largest influence on the uncertainty in the investigated quantities.