COMPARATIVE PRECISION OF GRAIN SIEVING AND PNEUMATIC CLASSIFICATION ON A SINGLE KERNEL LEVEL

Abstract

This article describes a comparative analysis of grain sieving and pneumatic classification and studies theprecision of the methods on a single kernel level. The mass distribution of individual kernels in barley samplesfractionated by a sieve and in a pneumatic classifier were determined. Grain samples of equal individual mass were firstfractionated with a sieve. Then, after coloring one of the fractions and remixing, they were separated in a pneumaticclassifier. Using the same coloring technique, the precision of sieving and pneumatic classification were studied. Whenthe samples were divided into halves, about 50% of the kernels classified as small when one method was used wereclassified as large by the other method. Ten to twenty percent of the single kernels were found in the other fraction eachtime, when compared with the first sieving or separation in the pneumatic classifier. For classifying samples, both sievesand pneumatic classifiers gave highly repeatable results. However, if it is required to fractionate a grain sample intonarrow classes or to take away a well-defined fraction within a sample, neither sieves nor pneumatic classifiers of thetypes used in this study can be used.