Humidity

Water vapor within a given space * Absolute humidity: The mass of water vapor in a specific volume of a mixture of water vapor and dry air. * Relative Humidity: Ratio of the partial pressure or density of water vapor to the saturation pressure or density, respectively, at the same dry-bulb temperature and barometric pressure of the ambient air. Ratio of the mole fraction of water vapor to the mole fraction of water vapor saturated at the same temperature and barometric pressure. At 100% relative humidity, the dry-bulb, wet-bulb, and dew-point temperatures are equal