High-precision flow densimeter for fluids at temperatures to 700 K and pressures to 40 MPa

A vibrating tube flow densimeter for measuring the density of fluids as functions of temperature and pressure is described. The apparatus allows relative density measurements to be carried out on 6 cm3 of solution in about 20 min with a precision of 30 ppm at temperatures to 700 K and pressures to 40 MPa. The accuracy of the densimeter has been verified by measurements on NaCl solutions. Good agreement with literature values was obtained.