Increasing Accuracy of pH Measurements by Image Processing Technique on Smartphones
DOI:
https://doi.org/10.55164/jgrdi.v1i1.714Keywords:
Color Spaces, Colorimetric Technique, pH Measurement, SmartphoneAbstract
This research demonstates a technique for measuring acid-base (pH) values from the color changes occuring on pH paper using smartphones. The purpose of this research is to increase the accuracy of the pH measurement from the reader’s visual evaluation to be close to the values obtained from the standard pH meter by using image processing technique on smartphones. The steps in the experiment are to take the images of pH papers with the smartphones’ camera and then to convert the color space of the captured images from RGB to the device independent CIE 1931 standard color space. A calibration equation was constructed to determine the pH values from the color intensities. In the experiment, six buffer solutions were tested and the color values were analyzed to determine the pH values from the generated calibration equation. From the experimental results, it was found that the error of pH values measured by the smartphone was less than 8.7% from the standard pH meter and the correlation coefficients were 0.9841 and 0.9901 for the HTC One and the Lenovo K900, respectively. Thus, the proposed colorimetric technique can increase the accuracy of the pH measurement using smartphones to be close to the values from the standard pH meter. This will be useful in the food industry where smartphones or Imaging equipment are used to increase the accuracy of products’ pH values by the image processing techniques.
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