DEW POINT • The temperature where relative humidity reaches a 100%, that is the temperature in which saturation occurs is known as Dew Point temperature. • In simple words, the temperature to which moist air must be cooled to reach saturation. • For e.g. condensed water is called dew, when it forms in a solid surface 15C • Shown here is the parcel of air, which is at 15C and has certain amount of water vapor inside. 13C 11C • Look at the image and notice that now when parcel of air is cooled , its capacity to hold water vapor reduces and relative amount moisture of air increases. • In other words, its relative humidity is increasing. 10C • When 10C is reached, parcel of air is holding as much water vapor as it can and is therefore saturated. • The relative humidity is 100%. • This temperature is the dew point temperature. • If parcel of air were to cool further, condensation would occur, because the air can hold no more water vapor at this temperature. • This condensation is visible to us because clouds and fog will form as visible water droplets condense out of the saturated air. An Example • If the air temperature cools to the dew point, or if the dew point rises to equal the air temperature, then dew, fog or clouds b egin to form. At this point where the dew point temperature equals the air temperature, the relative humidity is 100%. 4 Steps To Create Dew Point • You will need an aluminum beverage can, cutter or blade, water and a lot of ice cubes. • Cut a shiny aluminum beverage can in half and preserve the bottom portion for use as a receptacle. • Fill the can with tap water. • Add ice cubes to the water to effectively lower the can’s surface temperature. Stir the mixture gently and keep adding ice until condensation forms on the can’s exterior surface.