Research On Photoelectric Turbidity Detection System

The quality of water is closely related to our life,with the improvement of living standards and environmental awareness,the requirements of water quality are more stringent.Turbidity is an important indicator of water quality detection,which is caused by the presence of insoluble particles in water.The daily water used by residents is disinfected by water works.When the turbidity of water is high,it is not only easy to breed microorganisms such as bacteria,but also affect the disinfection treatment.Therefore,it is necessary to measure the turbidity frequently.At present,the market of turbidity measuring instruments is mainly occupied by foreign instruments.Foreign instruments are expensive,and after-sales maintenance takes a long time.Compared with foreign instruments,domestic instruments are cheaper in price,but there is a certain gap in accuracy and stability,domestic instruments are on the whole at an inferior position on the market.Therefore,on the basis of existing research,in order to develop domestic turbidimeters with low cost,high accuracy and stability has very important practical significance.This paper introduces the common detection methods of turbidity and the development status at china and abroad,analyses the principle of turbidity measurement,and completes the research and design of a photoelectric turbidity detection system by combining scattering method and transmission method.The whole system includes optical part,hardware part and software part.In the optical part,which is measured by combining scattering method and transmission method.The light path is designed,the emitting light source is near infrared LED,and the photoelectric receiver is photodiode.In the hardware part,STM32 is chosen as the core control chip,and the power module,light source driver module,signal processing module and peripheral module of single chip computer are designed.In the software part,C language program is used to realize each sub-module,including measurement control,data acquisition,data display.The data transmission to PC is through serial communication to facilitate data storage and analysis.Finally,the performance of turbidity detection system is evaluated by experiments.The experimental results show that the turbidity detection system which designed in this paper has good accuracy and stability and attained instrument standards.