User:Milton Beychok/Sandbox
The water dew point (or simply the dew point) of a gas mixture is the temperature, at a given pressure, at which any water vapor in the gas mixture will start to condense into liquid water. The water dew point of a gas mixture, at a given pressure, is often referred to as the point at which the gas mixture is saturated with water vapor (i.e., the gas cannot hold any more water vapor).
The dew point of a gas mixture is involved with its relative humidity (RH). A relative humidity of 100% indicates that the gas mixture is at its dew point and saturated with water vapor. A relative humidity of less than 100 % indicates that the gas mixture is not at its dew point and not yet saturated with water vapor. Contrary to the common notion that relative humidity only applies to the atmospheric air, it applies to any gas mixture containing water vapor.