一种测定土壤水分传感器空间灵敏度的新方法

his study presented a novel method to determine the volume of sensitivity(VOS) for dielectric sensors by frozen soil columns radially thawing fromoutside inward. The method is based on physical equivalence of the dielectric properties between soil drying-wetting and freezing-thawing transitions. We applied this method to determine/compare (i) the VOSs of two types offringe field probes (one tube type and one cone type) with sandy silt loamsamples at a middle level of soil moisture content (qv = 0.20 cm3 cm-3), (ii) the VOSs of the cone-type probe with sandy silt loam samples at three levels (qv = 0.10, 0.20, and 0.28 cm3 cm-3), and (iii) the VOSs of the tube type probe with three soil textural samples (sand, sandy silt loam, and silty clay). The determined radii of the cone-type sensor ranged from 3.0 to 4.1 cm and those of the tube-type sensor from 5.1 to 8.5 cm. These results could be beneficial for improving the technical design of soil dielectric sensors and understanding the effect of soil physical properties on the VOS.)