. Absorption of vapors and gases by soils . e thevapor pressures at the level in the bottle and at the lower watersurface W, respectively, and d is the density of the vapor. Althoughthis value is very small, it is theoretically of interest and might enterinto calculation when the time factor is large. Small changes in temperature would cause loss of water from theweighing bottle containing moist soil. If the temperature rises alittle this will first affect the desiccator near the outside wall, at A,figure 4. The increase in temperature momentarily reduces the rela-tive humidity, thus disturbin
. Absorption of vapors and gases by soils . e thevapor pressures at the level in the bottle and at the lower watersurface W, respectively, and d is the density of the vapor. Althoughthis value is very small, it is theoretically of interest and might enterinto calculation when the time factor is large. Small changes in temperature would cause loss of water from theweighing bottle containing moist soil. If the temperature rises alittle this will first affect the desiccator near the outside wall, at A,figure 4. The increase in temperature momentarily reduces the rela-tive humidity, thus disturbing the equilibrium. In order to restoreequilibrium water vapor moves from the interior of the desiccatornear B toward A. This produces at the same time evaporation of thewater in B and of the water at W in the bottom of the desiccator. Ifa slight drop in the temperature within the thermostat now takes placecooling will first occur at A, followed by supersaturation and finallyby condensation of moisture at A until equilibrium is again estab-. FlG. 4.—Drawing of desiccator containing soil sample. ABSORPTION OF WATER VAPOR. 21 lished. This cooling, however will not produce a condensationupon the surface of the soil equal in amount to the loss by evapora-tion due to rise in temperature. Thus a slow loss of water fromsoil will result. The thermostat was heated by an incandescent electric lamp, con-sequently a black soil might absorb sufficient radiant energy to main-tain its temperature slightly above that of the surrounding vapor pressure of the warmer soil moisture would be higher, anda distillation of water from B to W would result. Opening the desiccator for estimation of the moisture in soil wouldreduce the humidity and cause evaporation from the soil weighing. ABSORPTION data. The absorption of moisture by air-dry soils in an atmosphere sat-urated with water vapor is shown by the data given in Tables II, III,and IV for quartz
Size: 1608px × 1553px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherwashingtongovtprin
