柔性极板电容式液位传感器的研究和应用  

Research and Application of Flexible Plate Capacitive Liquid Level Sensor

作　　者：龙颖奇 蔡锦达[1] 何方正 张克西 姚忠林 LONG Ying-qi;CAI Jin-da;HE Fang-zheng;ZHANG Ke-xi;YAO Zhong-lin(University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学,上海200093

出　　处：《包装工程》2021年第23期189-198,共10页Packaging Engineering

基　　金：高水平大学建设-学科建设-医工交叉创新项目(10-20-309-402)。

摘　　要：目的为了解决传统硬质极板电容式液位传感器在曲面容器上性能不佳的问题。方法从寄生电容的基本原理出发,研发一种可以包覆于圆柱面容器的柔性极板电容式液位传感器,建立液位与电容量间的数学关系,完成相应的软、硬件设计,通过STM32与柔性极板电容式液位传感器之间的I;C通信,实现液位传感器的在线水位检测,完成传感器性能测试实验,包括线性度、重复性、迟滞特性,并提出一种基于该传感器的流量测量方法。结果该传感器工作稳定,具有良好线性度,重复性误差为2.70%,在有效测量范围的迟滞特性参数都小于1.69%。结论该柔性极板电容式液位传感器安装使用便捷、与容器外壁贴合度较好,且测量结果不受容器水平横截面积、待测液体成分的限制,可以实时监测连续液位的变化。制作的传感器可以用在直径20 mm和更小的待测容器上,也可用作微小流量测量。The work aims to solve the problem that the traditional hard plate capacitive liquid level sensor cannot be strictly attached to the curved container.A flexible plate capacitive liquid level sensor which can be closely attached to the curved container was designed according to the basic principle of stray capacitance.The mathematical relationship between the liquid level and the capacitance was established,and the corresponding soft and hard design was completed.Through the I;C communication between STM32 and the flexible plate capacitive liquid level sensor,the online water level detection of the liquid level sensor,and the performance test experiment of sensor were carried out,including performance indicators such as linearity,repeatability and hysteresis characteristics.A flow measurement method based on the sensor was proposed.The sensor worked stably with good linearity.Its repeatability error was 2.70%,and the hysteresis characteristic parameters in the effective measurement range were all less than 1.69%.The flexible plate capacitive liquid level sensor is easy to be installed and used,has a good fit with the outer wall of the container,and the measurement result is not limited by the horizontal cross-sectional area of the container and the composition of the liquid to be measured.The continuously changing liquid level can be monitored in real time.The sensor made in this article can be used on the container to be measured with a diameter of 20 mm and smaller,and can be used for micro flow measurement.

关 键 词：柔性极板 液位检测 传感器特性 I C总线 小流量监测 

分 类 号：TB487[一般工业技术—包装工程]