An Open-Source Solution for Water Conductivity Monitoring Using Arduino and Low-Cost Components

Código

XXVI-SBRH0756

Autores

Pedro Gabriel Grochocki Gabriel, RAFAEL DE CARVALHO BUENO, Mikael Souza Silva, Tobias Bernward Bleninger, Michael Mannich

Tema

F - Processos Hidrológicos e Monitoramento Integrado de Recursos Hídricos

Resumo

Water conductivity is a key parameter in water quality assessment, reflecting dissolved ion concentrations and serving as an indicator of both pollution sources and natural variability. Continuous, high-frequency monitoring of conductivity is particularly valuable for capturing short-term fluctuations caused by rainfall, contaminant discharges, or biological processes, patterns often missed by discrete sampling. However, the high cost of commercial conductivity meters limits their use in low-resource settings, educational projects, and citizen science initiatives. This study presents the development and evaluation of a low-cost, three-electrode conductivity sensor based on the Arduino platform and inexpensive, widely available materials such as stainless-steel electrodes. A segmented calibration strategy was employed to address the nonlinear voltage-conductivity relationship, combining linear regression for low-conductivity values and a power-law fit for higher ranges (0-50 mS/cm). Additionally, the effect of electrode surface treatment was assessed, showing substantial improvement in measurement accuracy, with mean relative error reduced from 56% to 18%. Although the sensor's absolute accuracy remains lower than that of commercial or some other low-cost designs, its performance is suitable for detecting abrupt conductivity changes associated with contamination events in freshwater systems. This makes it a viable tool for environmental monitoring where low cost and broad spatial coverage are priorities.