| 摘要 |
PURPOSE:To eliminate the influence due to the orientation of a fiber, and to measure precisely the water content by constructing a cavity resonator with a pair of waveguides of which the aperture parts are opposed with a small clearance in between, and inserting a fiber sheet into the small clearance. CONSTITUTION:A fiber sheet 1 is kept in the clearance between an upper waveguive 4 and a lower waveguide 6. Linear polarized waves, e.g. 3GHz, generated from an oscillator 16 are oscillated by an oscillating antenna part 3, and converted into circularly polarized waves by an upper phase shifting mechanism 5. And microwaves, as the circularly polarized waves, are oscillated always vertically to the surface of the fiber sheet 1. The circularly polarized waves, attenuated by water molecules in the fiber sheet 1, are converted into linear polarized waves by a lower phase shifting mechanism 9 provided to the lower waveguide 6. After passing through the lower waveguide 6, the linear polarized waves are received by a receiving antenna part 10, and then converted into an electrical signal which is converted into a water content value by an arithmetic part 12. The water content value of the fiber sheet is displayed on a displaying part 13. |
