The Design And Realization Of Instrument For Seawater Nutrient

Nutrients refer to a class of salts that have an important influence on life activities.Their content in seawater has a profound effect on the ecological cycle.All along,the detection methods and equipment for nutrients in seawater are hot spots for researchers.This dissertation was funded by the research and development of scientific research instruments of the central government.In order to meet the requirements of marine ecological research and environmental detection,we have developed a high-sensitivity detection,wide detection range,easy operation,good accuracy,small size,and convenient on-board nutrient detection instrument.Combined the research background,the development trend of the method and instrument used for nutrient detection was carefully studied and compared.A structure scheme based on spectrophotometric and flow injection analysis was designed.In terms of hardware design,it mainly adopts a modular design scheme and divides the overall design into optical modules,flow injection modules,control modules,signal acquisition modules,and temperature control modules.Among them,the signal acquisition module has designed three kinds of detection modules:photodiode,photomultiplier tube and spectrometer,integrating the advantages of spectrophotometry and fluorescence spectrophotometry.The independently designed optical path and photodiode detection module circuit ensure the signal to noise ratio of the acquired signal to the greatest extent.Finally,a prototype was designed and manufactured,and the stability of its detection module and light source was verified through specific experiments.Through the actual sample experiments of nitrite nitrogen and active phosphorus,the linearity,reproducibility and sensitivity of the instrument were tested.The test results showed that the instrument performance was good.