The Study Of Water Quality Detection System By UV Absorption

Water quality has always been a very concern in people's daily life,and water quality testing instruments have attracted more and more attention.The purpose of this paper is to design a high precision,low power,high stability,easy to use based on UV absorption method based water quality detection system.The work of this paper includes: the principle of the UV absorption method and detailed study the principle and Realization of the lock-in amplifier are studied in detail.The advantages of using lock-in amplifier in water quality detection system.Design a water quality testing system.By driving the signal to drive the light source,the solution in water is irradiated,and the light absorbed after the solution is converted to electrical signal through the detector.After the lock-in amplifying process,the DC signal which is related to the intensity of the collected light is obtained.The calculation of the concentration of the substance in the solution through the intensity of light.According to the principle of lock-in amplifier,the principle of UV absorption method and the simulation of Matlab,the water quality detection system using analog lock-in amplifier is designed.The principle of the digital lock-in amplifier is simulated,and the water quality detection system of the analog lock-in amplifier is optimized and upgraded according to the simulation results.The performance of the analog lock-in amplifier,the performance index of the detection system based on the analog lock-in amplifier,the performance of the digital lock-in amplifier and the performance index of the water quality detection system based on the digital lock-in amplifier are measured through experiments.At the same time,it solves the problem of temperature drift caused by the continuous work of the high-power chip and the long time work of the light source in the closed environment.The detailed analysis is carried out in combination with the simulation and the specific conditions.