摘要 |
A method of maintaining a given content of a substance A in an aqueous solution where it is continuously consumed and where the redox potential E, at least within the range of concentration used, approximately satisfies the equation: E = G + F(x) wherein x is the content of A, F is a function of x whose derivative dF/dx approaches zero when x assumes a high value, and G on the whole is independent of x but is influenced by other parameters, such as pH, temperature or the like. The addition of A is controlled in such manner that a set value of the redox potential is maintained. The set value is determined by increasing or decreasing the addition of A in a predetermined manner, whereupon the redox potential is measured, and the measured value is used for determining the set value. <IMAGE> |