The Detection Technology And Experimental Research Of A New Type Of Electrical Conductivity And PH Of Water Quality Parameters

This paper based on the detection of conductivity and pH of the two water quality parameters, surveyed the current measurement methods of solution conductivity and pH both at home and abroad, chose the absolute measurement based on Van Der Pauw theory and double pulse current method as the research method to detect the electrical conductivity of water solution and pH respectively, designed a water quality detection system can both apply for laboratory research needs and home detection, and carried on detection experiments of conductivity and pH in the system, to check practicability of the system. The main research contents of this paper are as follows:1) Since the lack of the reference material of low electrical conductivity in China, which disables the quantitation of low electrical conductivity, this paper chose the measurement method based on Van Der Pauw theory, and described the principle of the measurement method. On the basis of it, a circulation type measurement system with constant temperature for electrical conductivity of pure water was structured, which can avoid the influence of the outside atmosphere and temperature.2) After researching some kinds of methods for detection of pH, this study choose double pulse current as the research method. According to the principle of the method, and on the basis of the system design requirements, combined with laboratory research results of three-electrode system in recent years,we selected the appropriate working electrode, auxiliary electrode and a reference electrode,and designed the experimental installation based on three-electrode system.3) According to the requirements of system design, the study developed a set of hardware and software integration system. The design algorithm can quickly extract the feature points in the signal response information, realize the qualitative and quantitative analysis.4) Experimental study was carried out to detect the conductivity and pH of water parameters based on our self-developed detection system. Firstly, we tested repeatability of the electrical conductivity meter based on Van Der Pauw theory by a series of performance such as precision, stability and repeatability, and compares these performance parameters with commercial electrical conductivity meters domestic and overseas through measuring the electrical conductivity of standard material, and aslo verified the accuracy of the sytem to measure high purity water and actual sample. Then we also tested repeatability of the pH by a series of performance such as precision, stability and repeatability. The experimental results show that detection system can be widely applied to the detection of conductivity and pH in water.