Abstract
A simple dew-point hygrometer injecting a saturated salt solution is described. The dew-point hygrometer consists of a metallic vessel (∼200cm3), a U-tube manometer and a syringe. A gas to be measured is placed into the vessel, and then a definite amount of saturated salt solution known of the equilibrium relative humidity is injected in the vessel. The dew-point of the gas is determined theoretically from observed values of the pressure difference caused between the gas and the open air, the temperature of the gas and the atmospheric pressure. The other hand, using the gas known of dew-point, the equilibrium relative humidity of a saturated salt solution injected can be determined. Salts used in the experiments are NaCl, K2CO3. 2H2O, MgCl2. 6H2O and LiCl. The results of measurements of equilibrium relative humidity and dew-point are shown and discussed.
