Design Of A High Precision Automatic Online Instrument For Detecting Fluoride Ion

By the development of world science and technology,the speed up process of industrialization,people get huge financial benefits and enjoy factories’ variety products which provide daily convenience.The drinking water pollution and impacts on very important living environment,which maintain the survival of human body,around people,has reached a very bad level.Drinking water fluoride pollution is one of them.Statistics show that more than 200 million people in the world are drinking water that containing excessive F-,and about 80 million Chinese people among them.China has been the most extensive and serious country cause of drinking water-based fluorosis in the world.The implementation and continuous improvement of water fluoride determination technology has a very far-reaching significance.At present,the market has a fluoride detection equipment used in a single test method,poor degree of automation,large relative error between the test results and professional water quality monitoring station’s.These instruments within the pipeline system can’t solve the problem of cross-contamination,most of them using fixed calibration curve,fluoride electrode test results affected by external temperature,and the instrument can’t be networked,can’t achieve remote control and real-time water quality warning.This paper designed and developed a high precision automatic online instrument for detecting fluoride ion,can detect the content of fluoride ion in drinking water high-precisely.The use of multi-joint solenoid valve as the center of the automatic sampling line and low drift reduce noise isolation detect circuit,combined with computer fitting technology to achieve fast,high precision,good reproducibility of drinking water in the determination of fluoride concentration.In order to ensure a better detection accuracy of the instrument,this work designed an automatic injection pipeline with a small cross-contamination,accurate injection by use multi-joint solenoid valve as the center.Then the detection signal processing circuit for the fluoride ion selective electrode is designed to extract the weak signal submerged in the noise during the detection process.Finally,the temperature correction of the working curve of the fluoride ion selective electrode was carried out by using the regression analysis technique based on the least squares principle of the computer.High precision automatic online instrument for detecting fluoride ion through the actual water sample determination,the test results has high accuracy,and can eliminate the temperature and other factors on the detection results.