Ngadiman NLS, Abdul Rani R, Zulkifli ZF, et al. Preliminary Study of pH Sensor for Engine Oil Deterioration Detection Using Anodized Ta2O5 Nanotubular. ijie. 2022;14(3):229-240. Accessed April 28, 2024. https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/10403