热阴极低压汞灯驱动及光强稳定方法  

Drive and light intensity stabilization method of hot cathode low-pressure mercury lamp

作　　者：秦玉倩 段发阶[1] 傅骁[1] 黄婷婷[1] QIN Yuqian;DUAN Fajie;FU Xiao;HUANG Tingting(State Key Laboratory of Precision Measurement Technology and Instruments,Tianjin University,Tianjin 300072,P.R.China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《重庆大学学报》2021年第5期87-94,共8页Journal of Chongqing University

基　　金：国家重点研发计划资助项目(2017YFF0204800)。

摘　　要：热阴极低压汞灯可作为冷原子吸收测汞仪的紫外光源,但使用传统电子镇流器驱动时,其光强存在波动大、温漂严重等问题,不能满足痕量汞成分检测低检出限的要求,因此提出了一种热阴极低压汞灯驱动及光强稳定方法。构建了直流低压供电下的自激式电流馈电推挽谐振逆变电路拓扑,并基于等效电路模型设计电路参数,实现了汞灯预热启动和正常发光;以光强反馈方式构成了闭环控制系统,并对系统频域进行分析与优化设计,提高了光强稳定性。通过仿真实验验证了逆变电路的可行性,并搭建冷原子吸收测汞系统进行了测试,实验结果表明汞灯光强波动小于0.15‰,50 min内基线漂移小于0.06‰。Hot cathode low-pressure mercury lamp can be used as the light source for cold atomic absorption mercury detector,but the light intensity has problems of large fluctuation and serious drift when the lamp is driven by the conventional electronic ballast.This condition cannot meet the low detection limit requirement.Therefore,a lamp drive and light intensity stabilization method is proposed in this paper.To realize warm-up start and maintain normal illumination of lamp,a self-excited current-fed push-pull resonant inverter was constructed,and the parameters were designed according to the equivalent circuit model.To improve the light intensity stability,a closed-loop control system with light intensity feedback mode was established,and the frequency domain of the system was analyzed and optimized.The feasibility of circuit was verified by simulation.The stability of light intensity was tested by a cold atomic absorption mercury detector.The results show that the mercury light intensity fluctuation is less than 0.15‰,and the baseline drift is less than 0.06‰within 50 min.

关 键 词：热阴极低压汞灯 光源 驱动方法 稳定性改善 闭环控制 冷原子吸收测汞仪 

分 类 号：TH832[机械工程—仪器科学与技术]