| 摘要 |
PURPOSE:To measure the moisture in a sample such a paper, fiber or the like with high accuracy regardless of insertion directions by disposing two pieces of cylindrical vessels in such a manner that the vessels face each other to constitute a cavity resonator, providing a microwave feeding part and receiving part to the inside thereof, and generating the electric field in the vessels to the circular shape concentrical with the central axis of the vessels. CONSTITUTION:The 1st and 2nd vessels 12, 13 are disposed to face each other to constitute the cavity resonator 11 having a spacing of a distance lg for insertion of the sample. Dielectric rings 14, 15 having a high dielectric constant are fixed to the respective vessels 12, 13. The 1st and 2nd coupling loops 18, 19 are provided to the respective vessels 12, 13 and are connected to the inside walls of the vessels 12, 13 so that the loop planes thereof intersect orthogonally with the central axis of the vessels 12, 13. The microwave is transmitted from the loop 18 and is received in the loop 19. The electric field E by a TE013 mode is generated to the circular shape concentrical with the central axis of the vessels 12, 13 in the resonator 11 in this stage. Since the circular electric field is generated within the plane intersecting orthogonally with the central axis of the vessels in the above-mentioned manner, the moisture of the fiber sample having the directivity is exactly measured even if said sample is inserted to the instrument from any direction.
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