| 摘要: |
| 介绍了一种自行设计的，基于电流-电压四端法的便携式土壤电导率(EC)在线测试仪的开发情况。该测试仪包括土壤电导率传感器、控制与数据采集器和计算机应用软件等。传感器有4个电极，2个用于向土壤中输入恒流，另外2个用于检测与土壤电导率密切相关的电压降；控制与数据采集器把传感器产生的电压信号转换为数字信号，计算并显示电导率；计算机应用软件把接收到的数据存入Microsoft Access数据库。在实验室土槽内对该测试仪传感器的性能进行了测试，并与电导率仪测量结果进行了比较分析。结果表明，传感器输出电压与电导率仪测量值变化趋势一致，采用多种非线性数学模型对各组数据进行了曲线拟合，结果均在幂函数模型上获得最佳回归，测定系数(R^2)大于0．99。 |
| 关键词: 便携式 土壤 电导率 测试系统 系统开发 精细农业 数据采集器 计算机应用软件 |
| DOI：10.11841/j.issn.1007-4333.2003.04.097 |
| 修订日期：2002-11-28 |
| 基金项目:教育部留学回国人员科研启动基金资助项目 |
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| Development of a portable detector for soil electrical conductivity |
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| Abstract: |
| A portable detector for soil electrical conductivity (EC) based on four-electrode measurement method was developed. The detector includes 3 parts, which are the sensor, the control and data acquisition box and the data processing software. The sensor injects stable electrical current into soil and detects the voltage drop in it. The voltage drop can be used to estimate the soil EC. The control and data acquisition box has the functions of data acquisition, calculation and communicating with a PC. The data processing software is designed to put the data from the data acquisition box into a Microsoft Access database for analysis. Laboratory test showed that the system performs well. Several nonlinear mathematical models are applied in the regression analysis, and the best result is obtained from the model of power function, in which the determined coefficient (R2) is greater than 0.99. |
| Key words: soil,electrical conductivity,four-electrode,precision agriculture |
