DENSITY-INDEPENDENT MICROWAVE MEASUREMENT OF MOISTURE CONTENT IN STATIC AND FLOWING GRAIN

Conventional techniques for the determination of moisture content in grain often use small static samples to represent several tons of material. A more desirable alternative would be a method which utilizes continuous dynamic moisture measurement of the grain. The potential for making density-independent moisture content measurements in both static and flowing grain using microwave frequencies was evaluated in tests with soft red winter wheat over moisture contents from 11% to 19% (w.b.). Moisture measurements were predicted within ±0.7% for the static samples and within ±1.2% for wheat in a dynamic solid-flow condition. For suspended flow (aerated sample of grain) scatter became more apparent and the system accuracy decreased.