基于STM32的光学水中油检测系统设计

Design of Optical Oil-in-water Detection System Based on STM32

针对传统微量水中油检测系统检测精度低和体积大等问题,设计了一种基于STM32的光学水中油检测系统。系统利用矿物油的荧光效应,通过脉冲频率调制LED、微弱信号放大和数字正交锁相放大技术提取同频125 Hz的微弱荧光信号,用“一光源双探测”的光机结构消除光源对测量的影响,通过最小二乘法拟合水中油的质量浓度和相对荧光强度之间的关系,反演得到水中油的质量浓度。试验结果表明,该系统在0~60 mg/L内的水中油测量应用上具有较高精度,线性度为99.96%,为安全用水和环境保护提供了可靠依据。

Aiming at the problems of low measurement accuracy and large volume of traditional trace oil-in-water detection system,an optical oil-in-water detection system based on STM32 was designed.Using the fluorescent effect of mineral oil,the system extracted the weak fluorescent signal with the same frequency at 125 Hz by pulse frequency modulation LED technology,weak signal amplification technology and digital quadrature phase-locked amplification technology.The optical-mechanical structure of“one light source and double detection”eliminated the light source influence on measurement.The relation between oil-in-water mass concentration and relative fluorescence intensity was obtained by least square method,and oil-in-water mass concentration was deduced.The experimental results show the system has high accuracy in the application of oil-in-water measurement in 0~60 mg/L,with a linearity of 99.96%,and can provide a reliable basis for safe water and environmental protection.