The SKCS 4100 singulates individual kernels, weighs them, then crushes them between a toothed rotor and a progressively narrowing crescent gap. As a kernel is crushed, the force between the rotor and crescent and the conductivity between the rotor and the electrically isolated crescent are measured. This information is processed to provide weight, size, moisture and hardness information on an individual kernel basis.

Mean hardness index, weight, size, moisture and their standard deviations are then calculated from the single kernel data obtained on a 300 kernel sample. Hardness classification is determined from the average hardness index of the sample and the distribution of individual kernel hardness measurements within four hardness ranges as defined by the USDA/GIPSA. Results are obtained as mean values and standard deviations for each of the four parameters. Distributions of kernel data are illustrated in histograms. Further the SKCS 4100 classifies the wheat according to the Hardness Index.