2008 Volume 108 Pages 37-45
Time domain reflectometry (TDR) has been drawing a lot more attention as a way to identify the interfaces in between different dielectric media. To monitor water level (hw) with electrical conductivity (σw) and sediment surface level (hsed) in river by applying TDR, we developed a mathematical model to evaluate these properties and verified its effectiveness by measuring the dielectric constant of conductive fluid media and a soil material (sand) using TDR probes with different lengths. Although the determination of hw in extremely high-conductive media was technically incompleted, we could successfully determine hw,σw, and hsed with a probe in moderateconductive media. Judging from the relatively good agreement between properties evaluated from the model and observed data, we concluded the TDR measurement could be useful to evaluate hw, σw, and hsed with sufficient accuracy for practical use within an appropriate conductive range. In actual application of TDR to a river monitoring, the calibration of the probe used must be required to conduct accurate measurement based of the model.
