Pointing at the main problems existing in the utilization of point scale in soil moisture measurement,a linear scale measurement method was put forward and a sensor system of soil profile moisture information measurement was designed based on standing wave ratio method.With the help of a high frequency electromagnetic field simulation software HFSS and vector network analyzer,electric field distribution and impedance characteristics of sensor ring probe were analyzed and studied to determine the adaptation and sensitive areas of the ring probe.Two kinds of soil in different textures were taken as experimental samples,the output and the corresponding measured value of soil moisture sensors were executed polynomial fitting,and the results showed that the determination coefficient was above 0.99 and the steady and dynamic performances of sensors could satisfy the requirement of soil profile moisture measurement.The experiments of multi-layer moisture through the soil column showed the system could meet the soil profile moisture real-time measurements demand in linear scale and it had high measurement precision and stability.Meanwhile,the system was satisfied with needs of practical application and it had high aoolication oromotion value.%针对现有土壤水分点尺度下测量的局限性,提出了一种线性尺度下的土壤剖面水分测量方法,并设计了一种基于驻波比法的土壤剖面水分信息测量传感系统.借助HFSS高频电磁场仿真软件与网络矢量分析仪对传感器环形探头的电场强度分布情况与阻抗特性进行了分析研究,确定了环形探头适应性与敏感区域.以2种不同质地的土壤作为试验样本,对土壤水分传感器的输出与对应的测量值进行了多项式拟合,决定系数均达到了0.99以上,传感器的稳态与动态性能均能满足土壤剖面水分的测量要求.通过多层水分土柱穿层试验与对比试验表明,该系统能够满足线性尺度下土壤剖面水分的实时测量需求,具有较高的测量精度与稳定性.设计的土壤剖面水分线性测量系统的各项指标均达到实际应用的需求,具有较高的应用推广价值.
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