Physical Isolation as a Low-Cost Strategy to Mitigate Electrochemical Interference in pH–DO (Dissolved Oxygen) Multisensor Systems

The integration of pH and dissolved oxygen (DO) sensors in multisensor systems often causes electrochemical interference, which reduces measurement accuracy and stability. This study aims to analyze the interference phenomenon and evaluate the effectiveness of a simple physical isolation-based mitigation method. The proposed approach employed plastic shielding with several configurations, including no isolation, pH sensor isolation, DO sensor isolation, dual-sensor isolation, and variations in hole design (side and bottom openings). System performance was evaluated using drift and relative error parameters in the data acquisition system. The results demonstrate that physical isolation significantly reduced interference, with the dual-isolation configuration producing the lowest drift value of 0.03 pH/min. In addition, the side-opening design exhibited better performance than the bottom-opening design in stabilizing the measurement environment, reducing interference by up to 82.3%. These findings indicate that simple physical engineering approaches can serve as effective, low-cost, and easily implementable alternatives to electronic isolation techniques or complex algorithm-based methods. This research contributes to the development of more stable and practical multisensor water quality monitoring systems.