A new and reliable calibration method for vibrating tube densimeters over wide ranges of temperature and pressure

Measurement and prediction of speeds of sound of fatty acid ethyl esters and ethylic biodiesels

“…Measurement and comparison with literature values of speed of sound of toluene and cyclohexane at 25°C leads us to assume an accuracy of 0.5 m s À1 , as claimed by the manufacturer. In the case of density, besides the usual method recommended by the manufacturer of using dry air and degassed ultra-pure water at 293.15 K as reference fluids, a new calibration procedure thoroughly described elsewhere [31] was performed. The calibrants used were ultra-pure water and dodecane with certified density values issued by H §D Fitzgerald, with expanded uncertainties of 0.01 kg m À3 (coverage factor k = 2, providing a 95% level of confidence).…”

Thermophysical Properties of 1-Butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, [C4mim][(C2F5)3PF3], and of Its IoNanofluid with Multi-Walled Carbon Nanotubes

“…The density, ρ, and speed of sound, c, measurements were performed using an Anton Paar DSA-5000 vibrating tube densimeter and ultrasound speed analyzer with temperature control within 0.001 K and measured with an expanded uncertainty of 0.02 K (k = 2). The densimeter was calibrated with high-quality Millipore water and tetrachloroethylene (density-certified by H&D Fitzgerald), with the calibration methodology developed by Lampreia and Nieto de Castro 50 . Density values were corrected for the extra damping caused by the high viscosity of the mixtures.…”

High-temperature vapour–liquid equilibrium for ethanol–1-propanol mixtures and modeling with SAFT-VR

“…Liquid and vapour phase composition were determined indirectly by densimetry, calibrated according to the methodology described by Lampreia and Nieto de Castro [21]. Densities of the collected vapour and liquid samples were measured with an Anton Paar DSA 5000 M densimeter at atmospheric pressure and 293.15 K. The densimeter was calibrated with water (Deionised and degassed before use -Lab Production (Milli-Q), with a resistivity of 180 kV Â m) and tetrachloroethylene with an expanded uncertainty of 0.01 kg m À3 (k = 2) 1 , at atmospheric pressure, between 283.15 and 323.15 K. Furthermore, the calibration curve as a function of composition (third order polynomial of the molar function of ethanol) was obtained from published data [22].…”