The Intelligent Turbidimeter Employing Technology Of Modulating Light Magnitude Of Lamp House

The water is essential to people's life. In tap water process, turbidity must be measured and in many realm such as environment protection, sanitation, food-made, medicine, eletron, energy source and etc., the quantity of the suspended matter presented in water is limited to some extent. This quantity is measured in turbidity. Tubidity meter is used to measure turbidity. As a instrument measuring turbidity, Tubidity meter is widely applied to those industry mentioned above. According to statistic, a thousand of turbidity meter are needed in our country each year. However, acquirement of them to a great extent depends on import. Though those turbidity meter have satisfactory precision and reliable, they are complex, expensive and bulky.As computer technology dramatic development, measure instrument evolved from hand-oriented and digital screen-oriented instrutment to intelligent instrutment farther to virtual instrument which later decade appeared. Those instrument fully exploit the resource of computer, integrating computer's capability of processing data and controlling ability of hardware of instruments together. As a result, the hardware cost and bulk decrease, furthermore they are more flexible and easier to be proliferated than traditional measure instruments.In the dissertation, puting forward a method that employs modulating light as lamp house. In fact, it is application of signal process technology to turbidity measure. In other word, the signal acquired which consists of turbidity, background light and noise of circuit passing a bandpass filter, commutator and lowpass filter, then becoming a signal eliminated background light and noise of circuit. Farther in the dissertation, simulating the measure process in computer, and abtaining satisfactory results. On the basis of the analysis and the simulation above, implementing the turbidity meter. The software of the turbidity meter was writed in C++ language on Mirosoft Visual C++ 6.0 environment. The instrument fully exploits the capability of calculation, dealing with graph, displayment , saving data and printing. Computer automatically acquires and saves the characteristic data of hardware in the process of convert and transfers which used to revise nonlinear data later. By friendly interface between human and computer, calibration become very convenient. The reason to do so is that made precision of instrument less depends on linear precision of hardware. In additional even if the circuit and eletric component become aging, by nonlinear revising and calibrating anew, the instrument can easily restore its precision. In the aspect of hardware, the instrument mainly consists of singlechip, A/D convertor, detector and multiplexers. Singechip is the heard of hardware. It takes charge of comunication with computer, controlling A/D convertor, switching multiplexers and producing lamp house signal. The hardware of instrument is very simple. After all, the instrument to great extent depends on software and less on hardware. The instrument is unexpensive and less bulkly. The result abtained by using the instrument to measure turbidity indicated that the method that employs modulating light as lamp house combining with capabilty of computer can do satisfactory measure. It is worth to recommend.