Saturated air

From Swikipedia

Introduction

Moist air in which the partial pressure of water vapour equals the vapour pressure of water at the existing temperature is called saturated air. This occurs when dry air and saturated water vapour coexist at the same dry - bulb temperature.

The air consists of the water vapor or moisture at all times no matter what its temperature and pressure is. When we add more moisture to the air in an enclosed space at certain temperature, the air tends to keep on absorbing the moisture. However, after reaching certain stage, the air is no more able to absorb the moisture and all the extra moisture is converted into dew or fog. The air that contains maximum amount of moisture that it can hold at particular temperature is called as saturated air.

The quantity of the moisture that the air can hold depends on its temperature. The more is the temperature of the air, the more quantity of the moisture it can absorb.

References:

http://www.brighthub.com/engineering/mechanical/articles/39617.aspx