In marketing, the average moisture content of the grain bulk being bought and sold is important. Both the buyer and seller need to know how much of this expensive water they are dealing with. For storage, it is the highest moisture content that is present in the grain mass that determines to what extent and how fast storage fungi will develop and damage the grain. Using samples to describe the moisture content of a bin of rice assumes a uniform distribution of moisture. Representative samples, however, taken from a storage bin do not provide the range of moisture present within the bulk.
Direct methods determine the water content by removing the moisture.
For example, oven methods evaporate the moisture from the grain and determine the water content by the weight loss. Indirect methods, in contrast, require the measurement of an electrical property of the grain, either conductance or capacitance. The direct methods are considered to provide true measurement of moisture content. They are used to calibrate the more practical and faster indirect methods. Classification of grain moisture measurement methods.