Research On Electrical Conductivity On-line Measurement System For Seawater Desalination

Water crisis is a serious problem which our country is facing. Seawater desalination is an important way to solve the problem. The electrical conductivity is an important indicator parameter to ensure normal operation of seawater desalination system and measure the quality of desalinated water.A seawater desalination electrical conductivity parameters on-line measurement system has been studied in this paper. It analyzes the development of electrical conductivity measurements method at home and abroad, it studied the three main factors affecting the electrical conductivity measurement and an electrical conductivity measurement method based on the variable frequency excitation was proposed. And designed seawater desalination electrical conductivity measurement system based on embedded control, completed the system's hardware and software designing. A measurement pool with ultrasonic cleaning equipment was designed, completed the measurement circuit designing based on the AT91RM9200 core controlling, including the design of excitation source, the design of electrical conductivity measurement circuit, range the design of switching circuit, the design of the temperature acquisition, and the design of the A/D converting circuit. Completed software design based on embedded Linux operating system, including the A/D driver design, the main system measuring program design, touch screen controlling software design and data acquisition and processing program design, and completed the human-machine interface design based on touch-screen control system.Some experiments were designed in this paper, Including the experiment to measure the incentive frequency, the experiment to measure standard solution, and the experiment of analyzing system measurement precision. By these experiments, the system performance was researched and ready for the system optimization solution.In this paper, the electrical conductivity on-line measurement system was designed to achieve real-time monitoring of electrical conductivity parameter. The system realizes the conductivity parameter measurement integrated, intelligent and electrode auto cleaning function, the precision can achieve 2%, and in line with the development direction of water quality measuring instrument at home and abroad.