Key words: supercritical fluids, density measurement, high temperature media at high pressure, phase behavior
High temperature vibrating density gauge (VDG) for chemically active media is developed. The VDG operational principle is based on registration and analysis of natural frequencies of high pressure U-tube capillary filled with the media under
study. The location of the capillary inside the thermostat possessing ±0.1 °C temperature accuracy, that enables density measurements and phase behavior study of aggressive media at pressure and temperature ranges 0.1÷50 MPa and 20÷500 °C, correspondently. Carbon dioxide density measurements performed with the VDG below, near and above its critical point (31 °C), as well as water density measurements at temperatures up to 375 °C demonstrated good agreement to the data derived from interactive database of NIST (National Institute of Standards and Technology). Density data for water-methanol binary mixture at temperatures up to 300 °C are obtained.
doi:10.1134/S1990793109070136