低温介质下电容液位测量系统的研究

Research of Capacitance level Measurement System in Cryogenic Medium

摘要:

针对低温介质的贮存和使用问题,设计一种数字化的高精度电容液位测量系统样机。采用连续与分节相结合的方式对电容液位计的结构进行优化,系统的硬件部分以微控制器为核心,将电容的变化量转换为数字信号,实现与上位机的网口通信。通过电容标定工具和液氢对样机的性能进行验证,结果显示,系统的电容测量精度优于0.1pF,且能够有效分辨出1.37mm的液氢液位变化,满足低温介质液位测量的精度要求。

Abstract:

Aiming at the problem of storage and use of cryogenic medium, a digital prototype of high-precision capacitance liquid level measurement system was designed. The structure of capacitance level meter was optimized by combining continuous and segmented. The system’s hardware part took the microcontroller as the core, which converted the change of capacitance into digital signal, and realized the communication with the host computer by the network interface. The performance of the system prototype was tested and verified by the capacitance calibration instrument and liquid hydrogen. The results show that the capacitance measurement accuracy of the system is better than 0.1pF, and the liquid hydrogen level change of 1.37mm is able to be distinguished effectively, which meets the accuracy requirements of cryogenic liquid level measurement.