| The design of autonomous nutrient analyzer based on spectrophotometry is introduced in detail from the aspects of measurement principle, flow structure, and electronic control architecture. In view of the demand for long -term online monitoring of nutrients in unattended environment, the flow path design is optimized to realize the function of automatic calibration, and the reagent refrigeration and online filtering modules are added, which improves the stability of the reagent and realizes the long -term automatic filtering of water samples under turbid seawater. Through these optimization and improvement, the application scenario of the nutrient analyzer is expanded, the maintenance frequency of the instrument is effectively reduced, and the long-term in-situ online monitoring of the nutrient salt analyzer is realized. Standard samples and field seawater samples are used to comprehensively investigate the performance indicators of the analyzer. The results show that the analyzer has high measurement accuracy and precision for standard solutions, and the correlation of the analyzer with national standard method for seawater samples is higher than 0.9. At present, the analyzer is integrated and installed in the marine ecological monitoring station at the estuary of new Yongding River for long-term online monitoring. running stably and acquiring large quantities of nutrient monitoring data. |
