基于荧光猝灭原理的光纤溶解氧传感器研制

采用锁相放大技术研制了基于荧光猝灭原理的光纤溶解氧传感器,并组装了其测试系统。该系统采用高亮度蓝色LED作为光源,光电倍增管作为探测器,光栅光谱仪作为分光仪器,并使用SR830锁相放大器来检测荧光与激发光之间的相移。测定了相移差与调制信号频率、占空比之间的关系。实验结果表明,频率为60kHz、占空比为10%的矩形调制信号能使传感器的检测精度达到最大,对光纤溶解氧传感器的进一步研究具有参考意义。

Development of Fiber Optic Dissolved Oxygen Sensor Based on Fluorescence Quenching

Fiber optic oxygen sensor based on fluorescence quenching is developed and its test system is assembled. High- brightness blue LED is adopted as light source. Photomultiplier tube is used as detector. Grating spectrometer is used as spectral instrument and the SR830 lock-in amplifier is used to detect the phase shift between the fluorescence and excited light in this system. The dependence of phase shift on modulated signal frequency and its duty cycle are studied. The experi- mental results show that the rectangular modulated signal whose frequency is 60 kHz and duty cycle is 10% enabled the sen- sor detecting precision to achieve maximum. It is very significant for the further study of the optical dissolved oxygen sen- sor.