EXPERIMENTAL RESULTS ON AN OPTICAL PH MEASUREMENT SYSTEM FOR BIOREACTORS

Properties of a pH-sensitive membrane have been tested with respect to its possible application in bioreactors. The influences of ionic strength, buffer type, buffer capacity, color and turbidity of the solution on the response of the membrane are studied. The developed membrane shows high reproducibility and long-term stability. The pH-sensing membrane can be sterilized chemically and by using heat. With the present opto-electronic set-up, an accuracy of +/-0.1 pH between pH 6 and 10 can be achieved.