A vibrating tube flow densitometer for measurements with corrosive solutions at temperatures up to 723 K and pressures up to 40 MPa
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A new version of a vibrating tube flow densitometer has been designed permitting measurements of density differences between two fluids in the temperature range from 298 to 723 K and at pressures up to 40 MPa. The instrument is equipped with a Pt/Rh20 vibrating tube (1.6-mm o.d.) and a Pt/Rh10 transporting tube (1.2-mm o.d.) permitting measurements with highly corrosive liquids. The period of oscillation of the tube is about 7.5 ms, with a typical stability better than 10−4% over about a 1-h period over the entire temperature interval. The calibration constantK at room temperature is about 530 kg·m−3·ms−2, with a temperature coefficient of approximately −0.13kg·m−3·ms−2·K−1, and is practically pressure independent. It can be determined by calibration with a reproducibility generally better than 0.1%. The instrument was tested with NaCl(aq) solutions in the temperature range from 373 to 690 K for density differences between sample and reference liquid ranging from 200 to 2 kg·m−3; the corresponding errors are believed to be below 0.3 and 5%, respectively. A highly automated temperature control maintains the temperature of the tube stable to within ±0.02 K.
Key Wordsaqueous solutions critical point flow densitometer high temperature high pressure vibrating tube
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- 1.O. Kratky, H. Leopold, and H. Stabinger,Z. Agew. Phys. 27:273 (1969).Google Scholar
- 4.C. Bouchot, Ph.D. thesis (École de Mines, Paris, 1995).Google Scholar
- 13.R. F. Chang, and M. R. Moldover,Rev. Sci. Instrum. 67:in press (1996).Google Scholar
- 14.L. Hnedkovsky, I. Cibulka, and V. Hynek, in preparation.Google Scholar
- 16.R. Crovetto, R. H. Wood, and V. Majer,J. Chem. Thermodyn. 23:1139 (1991).Google Scholar
- 18.V. Majer, Lu Hui, R. Crovetto, R. H. Crovetto, and R. H. Wood,J. Chem. Thermodyn. 23:365 (1991).Google Scholar