MICROWAVE MOISTURE METER.

Conventional moisture meters for grains need a pair of antennae for transmitting and receiving microwaves. The grains are measured while they pass a narrow gap between the antennae. The flow of grain is not always smooth, resulting in low measurement accuracy. Furthermore, the gap is often clogged. In a newly developed device, the grains are measured while they are moving on a plate which includes a built-in microwave transmission line. The grains can flow on the plate without any obstacle, thus resulting in a high accuracy of lower than plus or minus 0. 7% (with unhulled rice having 12 to 22% moisture content). The microwave circuit is made of hybrid integrated circuits, making possible simple construction compactness, high reliability and accuracy. The frequency used is 10. 5 GHz.