土壤含水量的快速、准确测量问题由于其特有的复杂性至今尚未得到圆满的解决。将微波传输线阻抗变换理论应用于土壤水分测量，据此理论提出的测量方案从数学上证明其可行，所设计出的便携式土壤水分测量仪不仅成本低，而且测量精度满足使用要求。

A combined penetrometer is an appropriate tool to measure the soil cone resistance and the water-content profile. As arelatively new technique, acombined capacitance-penetrometer for the simultaneous measurement of cone index and soil water content was developed at the Department of Agricultural Engineering of Bonn University in 2002. The objective of this study was the evaluation of the effectiveness and applicability of the innovated penetrometer with a focus on three aspects: (1) A capacitance sensor with two electrode configurations was calibrated for silt loam, sandy loam, and sand. The calibration results show that both electrode configurations have sufficient water-content sensitivity, but soil-specific calibrations seem necessary.(2) Under laboratory conditions, the dynamic resolution and response of the capacitance-penetrometer were validated, and its radius of influence was determined.(3) The field measurement results demonstrate that this measurement technique can be used to improve the interpretation quality of soil cone index data.