Design Of Online Softsensoring Instruments

Treatment of the waste water from city life and industry is always an important problem in protection of environment. At present time, there isn't any instrument can measure some important parameters of the waste water, such as BOD. COD. in real-time. So it's very difficult to use auto-control techniques in the w^aste water treatment industry. In this condition, most waste water treatment factory control their production by workers' experiences, so the quality of the treated water is hard to be guaranteed and wasting of the resources is another disadvantage.In this thesis, we present a programmed instrument. By using the program, it establishes a mathematic relation between some parameters measured easily (such as temperature, concentration of dissolved oxygen. PH) and the parameters measured hard we need. By measuring those parameters easily measured and calculation, we can get the results of parameters we need almost in real-time. In this thesis, we introduce the design of this instrument:In chapter one, we introduce some background knowledge, including the Soft-Sensing Technique, the situation of the Soft-Sensing instruments model nowadays, and how this instrument will play its' role in so many instruments.In chapter two, we give an integrant design of the Online Softsensoring Instrument. Also a design suggestion is given for each part.I n chapter three, we introduce three kinds of instruments, and we decide to design the instrument with LCD - liquid crystal displayer. Later a mainly interface of the instrument is given.In chapter four, we introduce some methods of A/D conversion, and we take V/F as our A/D conversion.In chapter five, we introduce some knowledge of standard communication protocols, and we finally take the RS-485 mode.In chapter six. we introduce six types of memory, two running ways of the download program, and which is our choice. Later we also discussed security the download program and the security of the main program.