PH strip reader for beer samples based on image analysis

The measurement of pH is widely used in a number of sectors and applications to evaluate the alkaline or acidic level of aqueous solutions. Among the measurement methods, pH strips are widespread and affordable, although they have a limited accuracy compared to the pH meters. In this work, a method to evaluate the pH value of a test strip, based on image analysis, is presented. The proposed method exploits the color analysis to simplify the use and to improve the nominal accuracy of the test strips. The tests have taken into account the typical pH range in the production of beer, but the method can be extended on the whole range of pH values.