Archimedes Principle, volume measurement

A more accurate method for measuring the volume of a sample is to make use of Archimedes principle, where the difference between the sample weight in air w ir and its weight in a fluid divided by the density of the fluid Pfiuid-. gives the volume of the liquid displaced, which is identical to the volume of the sample. The density of the sample is then simply... 

IV.5.2.2.2 Density determinati n by the Archimedes principle The density determination of a polymer may be performed by a simple experiment based on the Archimedes principle. A polymer sample has been immersed in a liquid with known density. The upward pressure which is generated by immersion of the polymer sample into the liquid is equal to the weight of the displaced volume and this can be measured by a balance. A schematic drawing is given in figure IV - 40. 

With an irregular solid, like a rock, you can measure the volume by using the Archimedes principle. The Archimedes principle states that the volume of a solid is equal to the volume of water it displaces. Simply read the volume of water in a container, submerge the solid object, and read the volume level again. The difference is the volume of the object. 

Feldman and Beaudoin correlated strength and modulus of elasticity for several systems over a wide range of porosities. The systems included pastes hydrated at room temperature, autoclaved cement paste with and without additions of fly ash, and those obtained by other workers. Porosity was obtained by measurement of solid volume by a helium pycnometric technique and apparent volume, through the application of Archimedes principle. 

Lang, A. and M. R. Thorpe. 1989. Xylem, phloem and transpiration flows in a grape— application of a technique for measuring the volume of attached fruits to high-resolution using Archimedes principle. J. Exp. Bot. 40(219) 1069-1078. 

The porosity of the samples was determined using QuantaChrome Stereopycnometer with Nitrogen gas medium using the gas pycnometer test method ASTM D6226-98. This method measures the accessible cellular volume of a material. The remaining volume is that occupied by closed cells, cell walls, and unfoamed sohd polymer. A gas pycnometer is designed to measure the volume of sohd objects. This is accomplished by employing the Archimedes principle of fluid displacement to determine the volume. The displaced fluid is a gas,... 

More accurate density measurements may be made by instruments that take advantage of the principle of Archimedes, where the apparent weight of an object immersed in a fluid is diminished by that of the fluid displaced. In the simplest version of this experiment, a sinker of known mass and volume is immersed in the fluid while suspended by a wire from an analytical balance. More sophisticated versions may use a magnet to suspend the sinker or measure the difference between two sinkers of similar mass and surface area but different volume. With care and good control of temperature and pressure, such instruments can achieve uncertainties of 0.02% or lower for both vapor and liquid densities. 

Agglomerates often contain moisture. If this is the case, they must be dried prior to the determination of the solid mass, Mj. Also, with the exception of flat, cylindrical tablettes (see Section 8.4.3) and similarly well defined shapes, agglomerate volume can not be easily calculated. In those cases, the buoyancy of the agglomerate in a liquid is often measured. Since, according to the principle of Archimedes, the buoyancy is equal to the mass of the displaced liquid (under the assumption that the liquid does not penetrate into the agglomerate) the volume can be calculated as ... 

---