Detection and continuous monitoring of localised high-moisture regions in a full-scale grain storage bin using electromagnetic imaging

The performance of a radio-frequency grain bin imaging system, used for stored grain monitoring in an industrial scale (80 t) hopper-bottom grain bin, is investigated via a variety of experimental tests. The system is comprised of 24 magnetic field transmitter/receiver probes mounted on the inner walls of the bin. The system quantitatively images the dielectric properties of the grain which can then be used as indirect indicators of moisture content, temperature, insect infestation, and other anomalous physiological features. In this paper, we show that the imaging system is capable of detecting induced localised high moisture anomalies in 48 t of hard red winter wheat. These localised moisture anomalies consist of approximately 60 kg bags of wheat that have had their moisture content increased to a specified amount. Outside of these controlled regions the grain is heavily infested with red flour and rusty grain beetles. The moisture content is detectable within the images. Experiments with single and multiple regions of varying moisture content, as well as a ten-day study of the evolution of a single initial moisture region over time are presented.