Pycnometric vs. densimetric measurements of highly viscous protein solutions

Automated densimetric system: Measurements and uncertainties for compressed fluids

“…Several researchers [9,10,[45][46][47][48][49][50][51] have analyzed, mainly at atmospheric pressure, how density measurements through mechanical oscillator densimeters are affected by the sample viscosity, and it is thus necessary to apply a correction factor to experimental data. From their results, it is concluded that the correction factor depends not only on the sample viscosity but also on the specific design of the oscillator tube.…”

Temperature and pressure dependences of volumetric properties of two poly(propylene glycol) dimethyl ether lubricants

“…In this work, these parameters A(T) and B(T, p) were determined through the measurement of the oscillation period of a reference fluid and of the evacuated tube over all the experimental range, following the method developed An important feature concerning mechanical oscillator densimeters is the effect of the sample viscosity on the density measurements. The correction factor depends not only on the sample viscosity but also on the specific design of the oscillator tube [29,30]. For the DMA HPM model, Segovia et al [12] have obtained very recently, from data provided by Anton Paar, the following correlation equation:…”

Tris(2-Ethylhexyl) trimellitate (TOTM) a potential reference fluid for high viscosity. Part II: Density measurements at temperatures from (293 to 373)K and pressures up to 68MPa

“…Several studies of this effect [11][12][13][14][15][16][17][18][19] have shown that the shape of the deviation is similar for all the studied vibrating-tube densimeters from Anton Paar. However, the reasons for this do not seem to be well understood.…”

“…The effect of viscosity on the density measurements made by U-tube densimeters has been extensively studied experimentally [11][12][13][14][15][16][17][18][19] and, recently, the increasing interest in high viscosity liquids has intensified the awareness in this effect [15][16][17][18]. However, to the knowledge of the authors, no theoretical study has been published.…”

“…Retsina et al [20] also note that an analytical treatment of the oscillation of a U-tube is not feasible. As a consequence of the complexity of a theoretical description of the liquid viscosity effect on U-tube density measurements, only empirical studies [11][12][13][14][15][16][17][18][19] about this phenomenon have been found in the literature. The viscosity effect on density measurements depends on the tube characteristics, which implies that the correction to the density readings has to be obtained for every particular instrument.…”