Safrianti, E., Feranita, Nurhalim and Wahyu Dwi Reza 2022. Design of pH Measuring Equipment for Liquid Waste from Coal Mining Using Arduino Uno. International Journal of Electrical, Energy and Power System Engineering. 5, 3 (Nov. 2022), 61-66. DOI:https://doi.org/10.31258/ijeepse.5.3.61-66.