Measurement of the densities of complex fluids: results at temperatures between 288 K and 343 K and at pressures up to 30 MPa for each of two mixtures (crude oils) of specified composition

(p,ρ,T) of liquidn-octane obtained with a spherical pycnometer at temperatures of 298.03 K and 313.15 K and pressures in the range 0.7 MPa to 32 MPa

“…Figure 1 also shows the 100 cm 3 positive-displacement pump mounted inside the stirred fluid bath; we did this to reduce the effects of mercury migration discussed above and elsewhere. (1,2) The effective area of the positive displacement pump piston was determined by auxiliary experiments at a pressure of 13.789 MPa. The linear displacement l of the piston was obtained with a precision of 0.001·l, from a scale mounted on the pump.…”

“…Recently, (1,2) we published densities of five complex and compositionally characterized fluids obtained with a ''cylindrical'' pycnometer. Here we present measurements of mass density for n-octane obtained with a spherical pycnometer.…”

“…This geometry was chosen because we can, with linear thermal expansion and elastic constants of the cell wall material taken from the literature, more easily calculate the internal cell volume V c at a given temperature and pressure from one gravimetrically determined value of V c (T,p). In our previous work, (1,2) the mercury was expelled from a positive-displacement pump situated at ambient temperature into a cell located in a thermostat; the pycnometer and pump were separated by a valve. During these previous experiments the mass of mercury injected into the cell was compared with that determined gravimetrically and, usually, the value obtained by weighing was greater than that calculated from pump displacements.…”

“…Present address: Center for Applied Thermodynamic Studies, University of Idaho, Moscow, ID 83843, USA. 0021-9614/96/060637+10 $18.00/0 7 1996 Academic Press Limited differences never introduced an error in mass density of more than 6·10 −4 ·r (2) and was typically 2·10 −4 ·r. To reduce the effect of this systematic error, the cell was weighed after each isotherm.…”