Liquid volume measurement

The phase diagram of a typical black oil is shown in Figure 5-1. The lines within the phase envelope represent constant liquid volume, measured as percent of total volume. These lines are called iso-vols or quality lines. Note that the iso-vols are spaced fairly evenly within the envelope. ... 

LIQUID-VOLUME MEASUREMENT Measurement of grout on the basis of the total volume of solid and liquid constituents. 

Barrel Liquid volume measure equal to 42 U.S. gal, commonly used in measuring petroleum or petroleum products. 

Ellson et al. [7] used the method of focused acoustic energy to eject a pL droplet from a nanoliter-scale well the droplet diameter being also measured by a digital stroboscope. In their experiment, 20 pL droplets were ejected from 20 nL liquids. The accuracy of liquid volume measurement is determined by the accuracy of... 

Neutton diffiaction was performed on the D4c diffractometer [10] at the ILL at a wavelength of 0.4972 A. Glass samples of the same composition, for example all BTO samples, were loaded into a 5 nun inner diameter vanadium can. The total mass of samples at each composition is shown in Table 4.1. The average glass sample radius was L7 mm for the pure BTO and L4 mm for the doped samples. An anpty vanadium can, boron powder in a vanadium can, the empty belljar, and a nickel standard were also measured for calibralion and correction purposes. All meas-uronaits were made at room temperature. A sample packing fraction of 0.51 0.05 was determined from liquid volume measurements. All samples were corrected for... 

These containers are frequently filled using liquid volume measurement techniques. For ammonia, a 56 % filling density is equivalent to a liquid volume of 82%. 

Knoebel and Edmister used a six-bulb apparatus of this type. The second virial coefficient and the amount of gas were extracted from a least-squares analysis of a plot of pF against p the volumes of the bulbs had to be measured absolutely. Hajjar et al. used a similar technique, but measured the amount of sample directly. Attached to the series of glass bulbs was a calibrated capillary tube. The condensed liquid sample was contained over mercury in this capillary, and the liquid volume measured. 

Note 7. These containers are normally filled by liquid volume measurement techniques. A 56% filling density is equivalent to 82 liquid volume percent for ammonia. 

Some typical experimental setups for volume and density measurement are given in Fig. 6.3. Rarely is it possible to make a volume determination by finding the appropriate lengths. Almost always, the volume measurement will be based on a mass determination, as described in Chapter 7. For routine liquid volume measurement, common in the chemical laboratory, one uses volumetric equipment in the form of calibrated flasks, cylinders, burettes, and pipettes, as well as pycnometers. These instruments are usually calibrated for use at one temperature only. Their quality and use are described in many laboratory handbooks. Calibration is always done by weighing the instrument filled with water or mercury, or weighing the liquid delivered when the instrument is emptied. 

If the isotherm is of Type I with a sharp knee and a plateau which is horizontal (cf. Fig. 4.10) the uptake n, at a point close to saturation, say p/p = 0-95, is then a measure of the micropore volume when converted to a liquid volume (by use of the density of the liquid adsorptive), it may be taken as actually equal to the micropore volume. 

Fig 9 3 A simple laboratory set-up for observing the casting process directly. The mould volume measures about 50 X 50 X 6 mm. The walls are cooled by putting the bottom of the block into a dish of liquid nitrogen. The windows are kept free of frost by squirting them with alcohol from a wash bottle every 5 minutes. 

If the mobile phase is a liquid, and can be considered incompressible, then the volume of the mobile phase eluted from the column, between the injection and the peak maximum, can be easily obtained from the product of the flow rate and the retention time. For more precise measurements, the volume of eluent can be directly measured volumetrically by means of a burette or other suitable volume measuring vessel that is placed at the end of the column. If the mobile phase is compressible, however, the volume of mobile phase that passes through the column, measured at the exit, will no longer represent the true retention volume, as the volume flow will increase continuously along the column as the pressure falls. This problem was solved by James and Martin [3], who derived a correction factor that allowed the actual retention volume to be calculated from the retention volume measured at the column outlet at atmospheric pressure, and a function of the inlet/outlet pressure ratio. This correction factor can be derived as follows. 

Liquids have relatively low compressibility compared with gases and, thus, the mobile phase velocity is sensibly constant throughout the column. As a consequence, elution volumes measured at the column exit can be used to obtain retention volume data and, unless extreme accuracy is required for special applications, there is no need for the retention volume to be corrected for pressure effects. 

If the liquid was measured by volume, the same calculation should be used by substimting V, and V in the proper places. 

Parameter P is equal to the ratio of the liquid volume entrained and the sum of the volumes of this liquid and particles. Values of P are determined experimentally from measured settling velocities. In general, the smaller the effective particle size, the more liquid is entrained by the same mass of solids phase. For example, particles of carborundum with d = 12.2 //.m have P = 0.268 d = 9.6 ftm, p — 0.288 and d = 4.6 fim, p = 0.35. 

Tlic density (p) of a substance is tlic ratio of its mass to its volume and may be expressed in units of pounds per cubic foot (Ib/ft ) or kilograms per cubic meter (kg/nv ). For solids, density can be determined easily by placing a known mass of the substance in a liquid and measuring tlie displaced volume. The density of a liquid can be measured by weighing a known volume of the liquid in a gradmitcd cylinder. For gases, tlie ideal gas law (to be discussed in Section 4.6) can be used to calculate tlie density from tlie temperature, pressure, and molecular weight of tlie gas. 

In experiments with bubble-columns containing suspended sand particles with average diameter 0.12 mm, an increase in heat-transfer coefficient was observed with increasing sand concentration, maximum values of 6000 kcal/m2-hr-°C being measured for suspensions containing 50% sand (based on the liquid volume). 

In 1944, Foust et al. (F2) studied air holdup in water in baffled vessels agitated with a special impeller developed for gas dispersion. The impeller consisted of arrowhead-shaped blades mounted on a flat disk. The gas holdup was determined by measuring the liquid level before the air was introduced and while the air was fed at a point underneath the impeller. They found that the gas holdup ranged from 2% to 10% of the air-free-liquid volume. 

Wu, Ruff and Faeth12491 studied the breakup of liquid jets with holography. Their measurements showed that the liquid volume fraction on the spray centerline starts to decrease from unit atZ/<70=150 for non-turbulent flows, whereas the decrease starts at aboutZ/<70=10 for fully developed turbulent flows. Their measurements of the primary breakup also showed that the classical linear wave growth theories were not effective, plausibly due to the non-linear nature of liquid breakup processes. 

The experimental liquid volumes of the pure substances versus T are reduced with the aid of the e, r values of Table I (usually these volumes were measured under saturated pressure and they had first to be extrapolated to p = 0). The reduced experimental molecular volumes of A, Kr, CO, N2, and CH4 were plotted... 

The above rules can be similarly applied to the conversions of volume and length measurements. While the weight and volume measurements are the most commonly used, the measure of length is used in measurements such as the patient s height and body surface area. The liquid and length measures are provided in Tables 2.2 and 2.3. 

New as well as used volumetric apparatus, namely burettes, pipettes, volumetric flasks and measuring cylinders etc., employed in carrying out most of the pharmacopoeial assays should be extremely clean. It is particularly of great importance where small volumes of liquids are measured. 

The value of e0 is only constant for a fixed volume V of solution inside the calorimetric vessel. The change of e0 with V is primarily due to an increase of the reaction vessel wall in contact with the liquid as the liquid volume increases [ 197,200]. This change, de0/dV, which is constant for well-designed calorimeters [197,200], can be determined by measuring e0 as a function of V. Because it has been found that as expected, e0 and d 0/dV are independent of the nature of the liquid used in the calorimeter, they are normally determined by performing electrical calibrations with the calorimeter filled with different volumes of water [200]. The energy equivalent of the calorimeter at any point during a titration can therefore be calculated from... 

Comelli, F. and Francesconi, R. Isothermal vapor-liquid equilibria measurements, excess molar enthalpies, and excess molar volumes of dimethyl carbonate + methanol. + ethanol, and propan-l -ol at 313.15 K. J. Chem. Eng. Data, 42(4) 705-709, 1997. 

If the organic liquid saturation is measured as the volume of organic liquid per unit void volume, measured over a representative volume of the porous medium, then S, the fraction of pore space occupied by the organic liquid is... 

Hence, the temperature coefficient of k1 having been measured, for an absolute calculation of k only kt) and bo must be known, and not the heat of adsorption, X. At the moment we are concerned with b0. A simple statistical estimate can be based on the assumption that in the absence of adsorption energy the adsorption space is filled at a proportion given by the ratio of the molecular adsorption volume (liquid volume Fm) to the molecular gas volume... 

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