本文讨论了用电容传感器测量砂子含水率的原理,并推证了湿砂的等效相对介电常数的表达式.然后,提供了具体的测量方案.为了便于应用的微机进行数据处理,应用最小二乘法原理推导出实用的数学模型.最后,绘出程序框图和实验结果,说明该法是正确的,并有较高的精确度. This paper discusses the principle of using a capacitive sensor to measure the moisture content of the sand, and deduce the expression of the equivalent relative dielectric constant of the wet sand. Then, it provides a specific measurement program. In order to facilitate the application of the data processing of the microcomputer, the minimum The principle of two multiplications deduces a practical mathematical model. Finally, the block diagram and experimental results are drawn to show that the method is correct and has high accuracy.