Mesures de la masse volumique d'hydrocarbures grâce au densimètre à lévitation magnétique et à double contrepoids.

Currently most precise densimeter with magnetic levitation has limit of accuracy due to a magnetic force-transmission loss, by about 100 ppm of density. In this report, the authors present their new PVT property measurement system with originally developed magnetic levitation densimeter (MLD). They have proposed an improved method to eliminate the uncertainty caused by magnetic force working on diamagnetic fluid, by introducing dual sinkers and controlling their levitation height of the magnetic coupling. This technique can almost eliminate the force transmission error. The authors have constructed a new MLD with prescribed advantage, by designing a novel weight-exchange mechanism with a magnetic coupling. The experimental range is up to 345 K for temperature, 5 MPa for pressure, respectively. The experimental results with less uncertainty are compared with available equations of state for hydrocarbon refrigerants in order to evaluate their PVT property reproducibility.