Performance Analysis and Calibration of a New Low-Cost Capacitance Soil Moisture Sensor
Performance Analysis and Calibration of a New Low-Cost Capacitance Soil Moisture Sensor
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DOI：
10.1061/(asce)ir.1943-4774.0000449
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发表时间：
2012-07-01
影响因子：
2.6
通讯作者：
Soulis, Konstantinos X.
中科院分区：
文献类型：
--
作者：
Kargas, George;Soulis, Konstantinos X.
几种新开发的基于电容和频率技术的传感器简化了土壤含水量（θ）的实时测定。10 HS传感器是电容传感器的最新发展之一。然而，到目前为止，人们对这种传感器的准确性及其测量对土壤类型和环境因素的依赖性知之甚少。在这项研究中，10 HS传感器的性能进行了研究，通过实验使用已知的介电性能的液体和实验中的一组多孔介质表现出广泛的属性。还研究了10 HS传感器在双层体系中的响应。实验结果表明，有一个明显的仪器灵敏度土壤类型，表明需要个别土壤校准。提出了一套具体的校准方程的各种多孔材料的研究。结果表明，10 HS传感器能够提供相当准确的相对介电常数（ε（r））测量，但制造商的ε（r）校准方程，在一定程度上，高估了ε（r）在液体中的测量值的整个范围。还发现传感器之间的变异性相对较小。结果表明，制造商的校准方程用于测量。版本1低估了。而第三版估计过高，在所有检查的多孔材料。最准确的结果提供了建议的土壤特定的校准方程使用多点校准方程。然而，两点校准方程合理地表示。在所有测试的多孔介质中。在粗孔隙介质中，土壤水分随温度的升高而被低估，而在细孔隙介质中，土壤水分随温度的升高而被高估。在细孔介质中，温度依赖性更为重要。还检查了沙子中的电导率的影响，发现其可以忽略不计。最后，双层系统中的传感器的响应通常在较低λ（r）值处遵循折射平均方案，而在较高λ（r）值处遵循算术平均方案。DOI：10.1061/（ASCE）IR.1943-4774.0000449。(C)2012年美国土木工程师学会。
Several newly developed sensors based on capacitance and frequency techniques have simplified real-time determination of soil water content (theta). The 10HS sensor is one of the most recent developments in capacitance sensors. However, up to now, little is known about the accuracy of this sensor, and the dependency of its measurements on soil type and environmental factors. In this study, the performance of the 10HS sensor was investigated through experiments using liquids with known dielectric properties and experiments in a set of porous media exhibiting a wide range of properties. The response of the 10HS sensor in bilayered systems was also investigated. The experimental results suggested that there is a distinct instrument sensitivity to soil type, indicating the need for individual soil calibration. A set of specific calibration equations for the various porous materials studied were proposed. It was shown that the 10HS sensor is able to provide reasonably accurate relative permittivity (epsilon(r)) measurements, but the manufacturer's epsilon(r) calibration equation, to some extent, overestimates epsilon(r) in the full range of the measured values in liquids. The sensor to sensor variability was also found to be relatively small. It was shown that the manufacturer's calibration equation for measuring. Version 1 underestimates., whereas Version 3 overestimates., in all porous materials examined. The most accurate results were provided by the proposed soil-specific calibration equations obtained using the multipoint calibration equations. However, the two-point calibration equations reasonably represent. in all porous media tested. Underestimation of soil moisture with increasing temperature in coarse porous media and overestimation in fine porous media were observed. The temperature dependence was more important in the fine porous media. The effect of electrical conductivities in sand was also examined, and it was found to be negligible. Finally, the sensors' response in bilayered systems generally follows the refractive averaging scheme at lower epsilon(r) values and the arithmetic averaging scheme at higher epsilon(r) values. DOI:10.1061/(ASCE)IR.1943-4774.0000449. (C) 2012 American Society of Civil Engineers.