Abstract: An instrument for automatically and accurately determining the "test weight" of grain, utilizes a confined column having a constant cross sectional area with means for sequentially dumping a plurality of batches of grain from the column and weighing the batches as dumped, combined with means for detecting the height of the grain in the column before or after each dump and feeding the information as to the height and weight to a microprocessor to determine the weight per unit volume utilizing linear regression equations. The instrument also includes an infrared spectroscopic detection device for determining moisture, protein, and oil content.