IMPROVED CONCENTRATION MEASUREMENT METHOD USING CONSTANT POTENTIAL ELECTROLYSIS METHOD

摘要

PURPOSE:To measure concn. of an oxidizing or reducing agent without calibration, by feeding strictly specified amts. of a soln. to be measured and a standard soln. to a measuring system through a specified constant amt. sampling cock having 2 flow paths, successively measuring them, and obtaining its concn. in accordance with a prescribed calculation formula. CONSTITUTION:In the method of constant potential electrolysis for determining the concn. of an oxidizing or reducing agent, a determination vessel 2 is provided with an upper level switch 10 and a lower level switch 11, a constant vol. of diluent soln. 1 is added, and the vessel 2 is agitated electromagnetically. The constant vol. of soln. 1 put into the vessel 2 is circulated through a path 4 of a cock 3 and the circulation system 5 with a pump 14, and the electric current value X0 of the soln. 1 is measured. During this time, the soln. 6 to be measured is passed through a 3-way electromagnetic valve 7 and the path 8 of the cock 3 to wash a feed path 9 sufficiently. After the measurement of X0, the cock 3 is changed over the path 8 to the circulation system 5, and the soln. 6 is fed into the vessel 2 by the vol. of the path 8. The mixture is circulated and mixed, and its electric current value X1 is determined. Then, the constant amt. of standard soln. is operated likewise as the soln. 6 was operated to determine its current value X2, and the concn. of the soln. 6 is determined in accordance with the formula shown, where f is concn. of the standard soln. and k=sample vol. of standard soln./ that of soln. 6.