Please see the video on the previous page for more information! All the grain samples used for official standards are selected and hand-cleaned to ensure their credibility for use in the field.
The moisture content of each sample is determined in the laboratory using the official USDA Grain Inspection, Packers and Stockyard Association's air-oven method. After determining the moisture content, a tolerance is calculated according to the National Institute of Science and Technology's Handbook 44 and the standard is labeled for field use.
The inspectors use these prepared samples as their official standards in the testing of each moisture meter. Each standard is carefully handled to ensure its credibility and is only used to test eight meters before it is returned to the laboratory. Since actual live grain samples are used as standards in the field, each sample is retested upon its return to the laboratory to confirm sample integrity. A retest is performed to assure that field use of the sample has not altered its moisture content.
The grain moisture meter inspection program is part of the Metrology Laboratory in Raleigh and is managed by a Grain Moisture Program Supervisor and two field inspectors.