Humidity and hygrometry Specific concepts Absolute / Specific / Relative Dew point (depression) Psychrometrics General concepts Air Concentration Density Dew Evaporation Humidity buffering (Atm.) Pressure Liquid water Avogadro's law Nucleation Thermodynamic equilibrium Measures and Instruments Heat index Sat. vap. density Mixing ratio Water activity H. indicator card Hygrometer Dry/Wet-bulb temperature