基于共面电容的非接触式液位线性测量系统的研究

摘要

一种基于共面电容传感器的非接触式液位线性测量系统主要包括前端平面电容传感器的设计、中间电容信号转换电路、后级的单片机数据处理以及液晶显示功能设计。与传统的线性液位电容传感器相比较本系统所设计的电容液位传感器，传感器可以直接安装在密闭容器外面，避免与容器内的液体接触造成污染或腐蚀传感器等问题。设计中采用差分电容的设计方案提高了系统的抗干扰能力。该测量系统具有结构简单，灵敏度高，稳定性好，动态响应特性好，可以在高温、强磁场、强辐射环境下精确测量非金属密闭容器内液位的实时状态。该系统可以广泛应用于液位在线监测领域。%This paper designed a non-contact linear liquid level measurement system based on coplanar capacitive sensor. The system includes the coplanar capacitive sensor, the capacitance to voltage conversion circuit, the process of converted capacitance data and the liquid crystal display. Compared with the traditional linear liquid level sensor in this system design of the capacitance liquid level sensor, the sensor can be installed directly outside the airtight container, avoid contact with the liquid container which brings the problems such as pollution or corrosion sensors. Adopted in the design of the differential capacitance design scheme to improve the anti-interference a-bility of the system. The measurement system has simple structure, high sensitivity, good stability, good dynamic response characteristics, it can accurately measure the level of liquid in an airtight container in real time in high temperature, strong EMI environment. It can be widely used in the online monitoring of the liquid level.