This gives the relationship of chip moisture-content versus time during the drying process. It is used during the mathematical modeling process to determine how long the chips must be retained in each bed to attain a specific moisture-content.  The drying curve for wood chips can vary considerably with chip size and wood type, but the process to establish the curve is relatively easy.  Chips with measured moisture content are dried in a simple fluidized bed for a measured amount of time and then checked again for moisture content.  Several runs are necessary to get points at different times.  The air rate must be sufficient to remove the moisture as quickly as it is released from the chips. Equations to represent the drying curves are easily created using the Solver function in MS Excel so they can then be used in dryer model. The temperature effect on drying can be projected by several methods.