基于锁定放大技术的真空度检测系统  

Vacuum degree detection system based on locking amplification technology

作　　者：谭金博 于占东[1] TAN Jinbo;YU Zhandong(College of Control Science and Engineering,Bohai University,Jinzhou 121013,China)

机构地区：[1]渤海大学控制科学与工程学院,辽宁锦州121013

出　　处：《现代电子技术》2024年第20期33-38,共6页Modern Electronics Technique

基　　金：国家自然科学基金面上项目(61673071);2023年辽宁省教育厅高等学校基本科研面上项目(JYTMS20231630)。

摘　　要：针对中低真空环境真空度测量精度低的问题,在定温电桥再平衡法的基础上,提出一种交流定温锁定放大真空度检测方法。定温电桥的失调电压信号经过前置放大、带通滤波后进入相敏检测环节,利用锁定放大技术对采集到的失调电压信号进行处理。该方法能够提高检测系统的信噪比,使失调电压的测量精度获得提升。电桥的定温控制在XC866单片机中实现,采用继电反馈临界比例度法完成控制参数的自整定。最后,搭建了交流定温锁定放大真空度测试实验平台,并对真空检测的数据进行处理和标定。实验结果表明,交流定温锁定放大真空检测系统在10-1~103Pa范围内,真空度测量误差不超过15%,验证了所设计方案的有效性和可行性。In allusion to the low accuracy of vacuum degree measurement in medium and low vacuum environment,an AC fixed temperature locking amplification vacuum degree measurement method is proposed based on the fixed temperature bridge rebalancing method.The offset voltage signal of the fixed temperature bridge enters the phase sensitive detection after pre-amplification and bandpass filtering,and the collected offset voltage signal is processed by means of the locking amplification technology.This method can improve the signal-to-noise ratio of the detection system and enhance the measurement accuracy of the offset voltage.The constant temperature control of the bridge is implemented in the XC866 microcontroller,and the relay feedback critical proportionality method is used to realize the self-tuning of control parameters.An experimental platform for AC temperature locking amplification vacuum degree testing is constructed,and the obtained vacuum detection data is processed and calibrated.The experimental results show that the AC temperature locking amplification vacuum detection system can realize a vacuum measurement error within 15%in the range from 10-1 Pa to 103 Pa,which verifies the effectiveness and feasibility of the designed scheme.

关 键 词：电阻真空计 真空度检测 锁定放大技术 交流定温电桥 XC866单片机 参数自整定 

分 类 号：TN107-34[电子电信—物理电子学] TP23[自动化与计算机技术—检测技术与自动化装置]