Distributed Sensing of pH Based on Color Imaging of Dye Coatings

Abstract

There are few works on the distributed sensing of pH, although the point sensing of pH is well establishied. In this work, we propose a new distributed sensing system of pH based on color imaging of pH-indicator dye coatings. The RGB imaging data from a CCD color camera were related to pH using the x, y, z values of CIE chromaticity. The pH value at each pixel point was determined by artificial newral network pattern recognition method using the relationship between the xyz values and pH. It has been found that the use of phenol red/agar gel, methyl red/agar gel coatings shows satisfactory distributed sensing of pH on the coatings.