Oscillometric-densimetric measurement

As the pressure measurements in oscillometric-manometric experiments only are needed to calculate the density of the sorptive gas = p (p, T)) in a sorption equilibrium state, it seems to be worthwhile to consider direct measurements of (p ), for example by using the buoyancy of a sinker at a magnetic suspension balance. Experiments of this type can be called oscillometric-densimetric measurements . They can be recommended to measure solubilities of gas mixtures in swelling (polymeric) sorbing materials. A scheme for such measurements is sketched in Figure 5.15. Equations to calculate the total mass of gas (m ) sorbed in the sorbent mass (m ) and the volume of the mass (m + m ) are the same as those given for oscillometric-manometric measurements in the next section (4.3). 

From these equations the quantities (m, V ) can be calculated from measured values of(f2osc, p, T), leading via the thermal equation of state of the sorptive gas to its density (p = p (p, T)). All the other quantities included on the r.h.s. of (5.76, 5.77), namely (b, m . Am, m, V ) can be determined from auxiliary and calibration type experiments at the pendulum and the gas storage system respectively. Note that eqs. (5.76), (5.77) also holds for oscillometric-densimetric measurements mentioned in Sect. 4.2 in brief. 

In practice combined volumetric-gravimetric measurements have been fairly successful [0.31]. Also densimetric-volumetric and densimetric gravimetric measurements using magnetic suspension balances (2 positions and 3 positions types respectively) can be recommended. If swelling sorbent materials are considered (slow) oscillometric measurements are recommended. Chap. 5. In case of multicomponent sorption systems (N > 2) a gas analyzing system has to be used in any case. 

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See also in sourсe #XX -- [ ]

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