Visualization of pH Distribution Changes in Swollen Gel Membranes Based on Color Imaging

Abstract

We present a new pH distributed sensing system based on color imaging of pH-sensitive dye-doped hydrogel membrane. The RGB imaging data from a CCD camera were related to pH using the y value of CIE-xy chromaticity. The y-pH relationship were expressed as a first- or second-order function (calibration curve). The pH value at each pixel point was determined from the RGB imaging data using the calibration curve. The use of phenol red/ager gel membranes has been found to result in satisfactory distributed sensing of pH in the swollen gel membranes.