附加电阻法快速测定土壤含水率的试验  

Experiment on fast-measurement of soil moisture based on additional resistance method

作　　者：王晓雷[1,2] 胡建东[1] 江敏[3] 赵向阳[4] 胡敬芳[1] 赵媛媛[1] 

机构地区：[1]河南农业大学机电工程学院,郑州450002 [2]东南大学仪器科学与工程学院,南京210096 [3]河南农业大学生命科学学院,郑州450002 [4]河南机电高等专科学校,新乡453002

出　　处：《农业工程学报》2009年第10期76-81,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：河南省自然科学基金项目(0611030900)

摘　　要：为了消除电容土壤水分检测中电导影响,提出了基于附加电阻的高频电容土壤水分测定技术,分析了高频电容土壤水分传感器的机理,建立了基于附加电阻的高频土壤水分数学模型,通过求解土壤水分引起的电容因子,消除了电导的影响,设计了基于附加电阻的平行板电容传感器土壤水分测试电路,并进行土壤测试试验。结果表明:土壤水分引起的电容值与土壤的质量含水率在1%～22%范围内呈线性关系,且基于附加电阻的高频电容土壤水分的测试值小于2%。In order to eliminate the influence of conductance in measuring the capacitance soil moisture content, the high frequency capacitance soil moisture measurement technique based on the additional resistance was proposed. By analyzing the principle of the soil moisture sensor modulated with a high frequency, the mathematical model of soil water content using a high frequency based on the additional resistors was established. The measurement errors from this conductance were eliminated by solving the equations of capacitance factor from the soil moisture. A parallel board capacitive sensor detection circuit with additional resistors was designed, and the experiment of soil moisture measurement was conducted. The experimental result shows that the soil capacitance value from soil moisture is linear with the soil gravimetric moisture content by 1%-22%, and the soil moisture content value based on additional resistance can be measured below 2% error range of gravimetric moisture content.

关 键 词：电阻 土壤水分 电容 高频 

分 类 号：S24[农业科学—农业电气化与自动化]