| 摘要 |
PROBLEM TO BE SOLVED: To provide a measuring system which can measure in-line the composition of brackish water and the chloride ion concentrations of sea water and desalted sea water, using ion- selective electrodes, a density meter, and an electrical conductivity meter, in order to achieve savings of the power required for the control of operation of an electrodialysis vessel used in a salt manufacturing process and also to achieve performance control. SOLUTION: A measuring part is provided with ion-selective electrodes that react to calcium and potassium ions in brackish water and a reference electrode, a density meter A for measuring the density of the brackish water, and an electrical conductivity meter G for measuring the electrical conductivity of sea water and that of desalted sea water. An arithmetic part, such as a computer 1, is used to compute the chloride ion concentration of the brackish water from the measurement of the density of the brackish water. The electric potential of the calcium-ion-selective electrode for the brackish water and that of the potassium-ion- selective electrode is corrected on the basis of the density measurement to compute the calcium and potassium ion concentrations of the brackish water. From the chloride and calcium ion concentrations of the brackish water, sodium ion concentration is computed, and magnesium ion concentration is computed from the chloride, calcium, and sodium ion concentrations of the brackish water. The chloride ion concentrations of the sea water and the desalted sea water are computed from the electrical conductivity of the sea water and that of the desalted sea water. |
