Design Of Electrode Type Laboratory Conductance Salinometer

The electrical conductivity of solution is a basic Physical and Chemical Measures. In specific condition, The electrical conductivity has close relation with the Salt Contented in solution, TDS, and PH value. The measure of electrical conductivity is the core of Multiparameter water quality detecting system , the research of electrical conductivity has significant meaning.There are many methods of measuring Seawater's salinity. The electrical conductivity method plays important role in these methods .After the establishment of practical salinity scale 1978 , it becomes the main technology for the salinity measurement, because this method has many advantages, such as high accuracy,quick speed and easy for field measurement.This dissertation introduces the developmental situation on domestic and international salinity measure technology, fully analyzes and elaborates the principle of pre-salinometer, especially introduces the key technology and the difficulty in salinometer. The dissertation provides several projects and chooses the best one according to experimental result and principal comparison between these projects. This dissertation introduces the whole scheme,the hardware electro circuit design , software design and the realization of FPGA, the result of experiment on salinometer is preferred at the end of the dissertation.The dissertation is the optimization design of pre- salinometer, which uses balance bridge to measure relative conductivity, the sensitivity is 10-5. The former design has some problems about electrical circuit and hardware logic. Imprecise software algorithm causes inexactness and instability; therefore it hasn't good reliability and continuity. The main aim of this dissertation is to improve the accuracy, reliability and stability, optimize continuity by perfecting software and amending hardware.The first important research of this dissertation is how to amend the specific hardware circuit, with which to do unit experiment to complete the automatic zero adjustment of the benchmark. With this to improve the system performance.The second important research is to improve the hardware design of FPGA, especially the IP core design. It also emulates and debugs the IP core. In this design, most functions can be completed by hardware, so it can decrease the workload of the software and reduce delay and measurement error.Finally, In the software, researching the advantages and disadvantages of different waveform processing algorithm to optimize the software algorithm, so as to achieve the requirement of the salinity measurement solution and increase the automation degree of the system. The human-machine interface is optimized so operators can use it easily and conveniently.