介电溶液测试土壤水分传感器性能的实证研究

利用土壤等效介电溶液代替土壤测试与评估土壤水分传感器的性能,具有便捷、快速的优点。为验证传感器在介电溶液中的测试结果是否与实际土壤中一致,利用去离子水和2—异丙氧基乙醇(2-isoproxyethanol)或二氧六环(dioxane)2种溶液混合,配制了一系列等效土壤体积含水率为0.9%~51.8%的待测介电溶液,同时取广州地区的典型红壤和雷州半岛的典型砖红壤,配制一系列与介电溶液等效含水率相对应的土样,分别从电气特性、与土壤含水率的函数关系、温度变异性和稳定性4个方面测试传感器的性能,并将介电溶液中的测试结果与2种土样中比较。实验结果表明:介电溶液中的测试结果与红壤和砖红壤中基本上一致,介电溶液在某种程度上可以代替土样进行土壤水分传感器的性能测试。

Empirical study of performance test of soil moisture sensor using dielectric solution

It has advantages of convenience and rapidity when~ using soil equivalent dielectric solution instead of soil to test and evaluate performance of soil moisture sensor. To verify whether the measurement result measured in dielectric solution is consistent with that measured in actual soil, a series of dielectric solution whose equivalent soil volumetric water content is 0.9 %-51.8 % is prepared by mixing deionized water with 2-isoproxyethanol or dioxane; two kinds of soil samples whose soil volumetric water content corresponds to equivalent soil volumetric water content of dielectric solution are prepared by using typical red soil in Guangzhou region and typical laterite in Leizhou peninsula as material respectively;and performance of soil moisture sensor is tested in three kinds of medium which are dielectric solution, red soil samples and laterite samples respectively from four aspects such as electrical characteristic, function relationship with soil water content, temperature variability and stability, and then the results measured in dielectric solution are compared with that measured in the other two kinds of medium. Experimental results show that test results in dielectric solution are basically consistent with the test results in red soil samples and laterite samples, and dielectric solution can replace soil samples to test soil moisture sensor performance to some extent.