Grain moisture testing at Minnesota grain elevators is performed with an instrument that measures changes in electrical conductance when a grain sample is placed within the instrument, between two conducting surfaces. The device then measures the change in electrical conductance because of the grain sample, and uses predictive algorithms to estimate the moisture level in the grain.
While this process is fast and quite accurate, farmers may have some questions about its reliability.
As with any instrument, several factors influence the accuracy of its measurement, including relative humidity, cleanliness of equipment, type of grain, ambient temperature and grain temperature.
Up-to-date calibration of equipment is also vital to ensure accurate moisture readings. The United States Department of Agriculture (USDA) has resources that provide the most recent calibration files, as well as directives for updating the equipment.
Farmers who have concerns about the moisture readings at their elevator are encouraged to have an official USDA sample taken and sent off for lab testing or USDA analysis. More information on that process can be found here: https://www.ams.usda.gov/services/fgis/inspection-services