土壌吸着水分系の誘電的性質

抄録

This study aims at clarifying the properties of soil water under the adsorbed state. For this purpose, it seems to the writer that making use of dielectrical properties is the most convenient. Then, study was carried in this way.
(1) The following experimental apparatuses were used:
(a) Bridge circuit.
(b) Double resonant circuits.
(2) The sample soil is of kaolinite type, the specific gravity and the specific surface area of which are 2.66 and about 42 m²/g, respectively.
(3) The relation between the packing ratio and capacity of the quite dry soil is linear as shown in Fig. 6 (C=3.02+10.2P). Using Drude's formula, dielectric constant of the quite dry soil only was obtained as 4. 4.
(4) The relation between the packing ratio and capacity of wet soil is also linear. But its dielectric constant cannot be obtained by physical means.
(5) As the packing ratio increases, tan δ of a soil-water system becoms greater even for identical moisture ratio. From these results, the determination of the soil in the same state becomes necessary for physical properties of adsorbed water.
(6) From the viewpoint of dielectric constant, adsorbed water seems to change qualitatively from about the second layer from the surface of soil particle.
(7) It is reflected in tan of soil-water system that the minimum relative humidity for finishing the monolayer water adsorption of soil is about 20%.