On-line pH Measurements of Near-Neutral Solutions by a Disposable Polymer Based ProbeSensors

An on-line optical pH sensor for the measurement of near-neutral solutions is presented. It consists of a disposable polymeric probe, encapsulating the fluorescein O-methacrylate 97 %, which is used as the indicator. The interrogation of the sensing element and the collection of the signal of interest is performed trough the use of an ad hoc optical head. Finally, a driver, front-end and signal processing electronics has been designed and realized to acquire and process the information of interest