SYSTEM FOR SENSING IONS IN AQUEOUS SOLUTION

摘要

The system for sensing ions in aqueous solution such as an electroplating bath includes a light source (18) which delivers light including a selected wavelength through a series of optical fibers (20, 24, 26, 32) to probe (14). The probe is partially immersed in the solution (12) and the light is delivered through the solution in the space (94) between prisms (82, 92). The return light is conducted by optical fibers (32, 38) to detector or opto-electronic transducer (44). A portion of the original light is diverted by splitter (22) through fiber (42) to opto-electronic transducer (46) so that a comparison of the signals determines the amount of light in selected wavelength is absorbed in the solution due to ions thereon. The signal processing unit (40) is preferably enclosed in an electromagnetic protected area (16) to avoid the adverse EMI and corrosive atmosphere effects near the electroplating tank (10).