As the name implies, grain moisture testers are instruments used to measure the moisture content of grain. They are also known as grain moisture meters. Grain moisture is measured in percentages. For example, field corn is best stored at 13%-15% moisture.
Why test grain moisture?
Grain crops such as corn are tested for moisture levels for a number of reasons. Corn that is stored when too wet will spoil and grow mold. Thus, most corn is dried before it is stored. The wetter the corn is when it is harvested, the more it will have to be dried, resulting in higher fuel costs. Over-drying can also harm grain quality. Moisture testing, therefore, is important before and during harvest as well as during transport and storage.
How does a moisture tester work?
Most grain moisture testers work by measuring electrical conductivity. Hand-held or portable testers are handy to take measurements in the field.
Bench-style moisture testers are generally larger, more powerful, and more precise, such as those at a grain elevator, which are state certified. Many moisture testers require grain to be poured into a pan or chamber. Others work by inserting probes into the grain.
Testing by instinct
Many farmers use yet another way to check the moisture level of their grain in the field. They will harvest a kernel or bean and check it by popping it into their mouth. Biting the seed can give a sense of the moisture content. While not as accurate as a tightly-calibrated moisture tester, it can be a quick way to decide if the crop is almost ready to harvest.