DETERMINATION OF THE DISTORTION COEFFICIENT OF A 500 MPA FREE-DEFORMATION PISTON GAUGE USING A CONTROLLED-CLEARANCE ONE UP TO 200 MPA

摘要

Cross-float experiments between a 500 MPa free-deformation (FD) piston gauge and a 200 MPa controlled-clearance (CC) one were carried out at a series of system pressures and jacket pressures. The two characteristics of the CC piston gauge, the zero clearance jacket pressure and the jacket pressure coefficient, were determined based on the Heydemann-Welch model. After that, the pressure dependence of the effective area for the FD piston was calculated using the cross-float data, from which the pressure distortion coefficient was determined to be 8.46×10~(-7) MPa~(-1). The result was about 19% larger than the one obtained by the Lame equation.