基于单光源频域荧光寿命的水体溶解氧浓度检测方法

现有的光学溶解氧浓度检测方法中光路及电路结构复杂,本文提出了一种单路光源的频域荧光寿命的溶解氧检测方法.采用单路光源的光学结构实现水体溶解氧浓度的检测,简化了光路及电路结构,改进了溶解氧浓度检测算法,降低了整体检测过程的计算量.设计对比实验对方法进行验证,实验结果表明:单光源的频域荧光寿命的检测方法与DOP1光学溶解氧分析仪相比,在0~9mg/L范围内,实际检测误差降低至0.04mg/L;衡量稳定性的检测标准偏差为0.007mg/L,同比降低了36%;采用快速傅里叶变换以及改进的溶解氧浓度计算方法,配合优化的电路及光路结构,在达到90%稳态时响应时间平均缩短了12s,浓度上升和下降时的响应速度分别提升为40%和28%.该方法具有较好的检测精度、稳定性以及响应速度.

Detection Method of Dissolved Oxygen Concentration in Water Based on Single Source Frequency Domain Fluorescence Lifetime

To reduce the complex optical path and circuit structure in optical dissolved oxygen concentration detection system,this paper proposes a methodology for detecting dissolved oxygen by frequency-domain fluorescence lifetime. The single-channel light source is used to detect the concentration of dissolved oxygen in water,which simplifies the optical path and circuit structure,improves the dissolved oxygen concentration detection algorithm and enhances the efficiency of inspection process.The effectiveness of the method is evaluated.Comparing with the results from an optical dissolved oxygen analyzer,our proposed method performed better in terms of the detection error(reduced from 0.1 mg/L to 0.04 mg/L in the range of 0~9 mg/L)and the stability(the standard deviation is decreased by 36% to 0.007 mg/L).Leveraging the implementation of a fast Fourier transform-based algorithm,the response time was reduced by an average of 12 seconds as steady state reached 90%,the response speed was increased to the percentage of 40%at the rise of concentration and 28%at the fall of concentration separately.The methodology demonstrated the effectiveness of detection accuracy,stability and response speed.