Erweiterung des dynamischen Meßbereichs von FIA-Systemen zur Steuerung diskontinuierlich geführter chemischer Prozesse

Summary

Concentrations of starting materials and products in batch processes often change over a range of three or more decades through the production. On-line monitoring of these processes should cover the whole range, but the needed precision in the different ranges is dependent on the task of the analyzer. Flow Injection Analysis offers different simple techniques to fulfill such requirements. This, together with other advantages, i.e., high analysis frequency, adjustable chemical selectivity as well as sensitivity and baseline-corrected measurement, makes the FIA technique useful for on-line analyzers in pilot- and production plants. General concepts to achieve expansion of the dynamic range of FIA systems are presented. Two general applicable methods using gradient techniques are explained and their usefulness is demonstrated with examples of industrial applications.