Development of Nondestructive Moisture Sensor for Agricultural Products Using Hydrogen NMR : Feasibility Experiments

수소자기공명원리를 이용한 비피괴적 농산물 함수율 측정장치 개발을 위한 기초실험

Nuclear magnetic resonance(NMR) was used to study a feasibility test for the possibility to develop a moisture sensor applicable for agricultural products such as raw and powdered grain. Samples of wheat flour and brown rice were tested with a 200MHz hydrogen NMR. The samples were loaded into 5mm NMR glass tubes and $30^{\circ}$ pulses were supplied to get resonance signals. Hydrogen spectrum intensities of the samples were compared to moisture content measured by a drying oven method. High linear correlations were obtained between the hydrogen spectrum intensity and moisture content. Therefore, moisure contents of agricultural products could be measured nondestructively utilizing the NMR principle. A low-cost design concept of the moisture sensor with the NMR principle was proposed for a practical use.