Research And Design Of Scattering Underwater On-Line Turbidimeter

The water quality is important to people's health and the quality of industry production. Turbidity is one of the most important water quality evaluation parameters. However, the water environment in our country is in a terrible position now. To protect and improve the water quality, the water environment on-line inspect system is being developed in our country. In this background, an on-line underwater scattering turbidimeter has been designed for on-line environment inspect system.Firstly, the concept of turbidity, the significance and unit of turbidity measurement are introduced. After analysis of several measurement methods, the scheme of scattering light measurement is fixed. Then, the mathematical relation between turbidity and scattering light is deduced. Moreover, non-linear compensation and the magnitude of emitted and received angle are discussed.Secondly, the hardware design of turbidimeter is introduced. The selection of optical sensor, the signal processing circuit, the structure and hermetization of the probe are explained in detail in the section of underwater probe of turbidimeter. The probe outputs pulse signal after changing scattering light signal by I/F converting. Pulse will be transmitted to the MSP430 microcontroller for furthering processing.Lastly, the software design of turbidimeter is introduced. The program in MCU is complied in C language. The C program has the function of data collection, processing and displaying. And then the turbidimeter can be calibrated easily. Furthermore, through the serial port, we can transmit the turbidity data to PC for more processing by application program developed by VC++ on PC.