Continuous monitoring of the concentration of complex solutions - by using selective electrodes immersed in a constant volume cell

摘要

A continuous constant stream of soln. from the main flow is mixed with a fixed amt. of dilutant, e.g. de-ionised distilled water, and pumped to a constant vol. cell. A selective electrode for each solute, the concns. of which it is required to measure, protrudes into the cell and the ionisation concn. is fed to a pH meter. The pH meter gives out in turn, an analogous voltage "u" which is relayed to a calculator. This calculator, using the equation: calculates the concn. of the solute in the undiluted stream from the signal obtd. from the diluted flow, and transmits the value to a recorder. Used for continuous determination of concn. of ionised solutes in complex solns. esp. liq. streams from reactors, e.g. measurement of HBr in an aqs. soln. formed by hydrolysis of Ca Br2 to produce hydrogen. Gives accurate measurement within 2% error and the response time for the measurement is short and depends on the distance of the cell from the sample point. Allows continuous checks of solns. with no limit on the concn. of the solute in soln.