ABSTRACT
Water, known as H2O, covers 70% of our earth and consists 65% of our bodies; it is extremely important in our lives. Water is achromatic and transparent, and it has three phases (gas, liquid and solid) depending on the temperature and pressure. Generally, water is categorized into two classes; bound water and free water. Adsorption water is entrapped by particles mainly by the hydrogen bonding between free water molecules and water molecules entrapped by particles. Contrary to the bound water, the free water captured by particles with relatively weak bonding strength, and is called adhesive water or swelling water. In a particulate system, damping condition by the free water is categorized into funicular, capillary and slurry states. The available method for measuring the moisture content is strongly dependent on the water existing form. The simplest way of measuring moisture content of particles is to measure weight loss after drying.
