The article about pH meter based on Raspberry Pi 3 has been created. This instrument serves as a measure of acid base levels of solution capable of displaying a GUI ( Graphic User Interface ) based interface programmed in the Raspberry Pi 3 System On Chip with the Python programming language. The purpose of this research is to innovate Raspberry Pi 3 based pH measuring device, to create interfaces and store pH measurement data based on Raspberry Pi 3 and Python programming language, find out the results of heuristic analysis on pH meter measuring instrument innovations, and determine the accuracy of the pH meter based on Raspberry Pi 3. The method used to pH sensor chararacterization in making this measuring instrument is heuristic method.The characterization sensor result show that the accuracy value of the pH sensor is 99,97%, the precision value of the pH sensor is 99,99%, the sensitivity value of pH sensor is 6,45 mV/pH, the correlation value of the pH meter is 99,89%. Based on the result of the analysis that has been carried out, it can be conclude the innovation in pH measuring device that are made have a good accuracy and can measure well.