Humidity fixed points of binary saturated aqueous solutions

摘要: An evaluated compilation of equilibrium relative humidities in air versus temperature from pure phase to approximately 105 pascal (1 atm) pressure is presented for 28 binary saturated aqueous solutions. The the solutions range about 3 98 percent. Using a data base 21 separate investigations comprising 1106 individual measurements, fits were made by method least squares regular polynomial equations with two through four coefficients. Equations and tables are along estimated uncertainties correlated results. Research, hygrometer calibration, testing material conditioning often require accurate control humidity working space. common methods controlling accurately use either generator (1A)1 or equilibration closed space chemical system (IB) which produces desired vapor pressure. Humidity generators tend be expensive complex whereas systems that provide fixed points relatively inexpensive simple control. Among used this purpose sulphuric acid solutions, glycerine water single salt Each such solution offers degree adjustment can achieved changing its concentration. On other hand, special problems associated solu- tions because their concentrations must measured controlled. Not only concentration determined initially but presence any sources sinks controlled even initial equilibra- tion process alter especially useful chemi- cal involves (primarily salts) solute highly non-volatile. At temperature, does not have determined. By provid- ing excess solute, will remain modest sinks. Where solid phase, it easy determine there indeed saturation. Due ease use, popular Since given provides one (RH) at different selecting another appropriate salt. Though much on