Research on an Electrochemical Salinity Sensor with Indium-Tin-Oxide Conductive Ceramic Electrodes

Abstract

Salinity is a critical metric in aquatic environmental monitoring because it can fluctuate owing to water pollution or the presence ofharmful substances. In this study, a salinity sensor based on a conductive ceramic film made of indium tin oxide (ITO) is proposed toaddress the issues of contamination and corrosion commonly observed in conventional salinity sensors that use metal electrodes. Byimproving the operational stability and measurement reliability, the proposed sensor offers a robust alternative for salinity monitoring. The sensor was fabricated using an efficient semiconductor process, comprising two quartz substrates with the ITO film deposited onthem in a facing configuration. The salinity levels were varied from 30 to 40 practical salinity units (PSU), and the sensor was testedunder both direct and alternating currents to evaluate the changes in conductive resistance and impedance between the electrodes. Theresistance changes exhibited strong linearity with an average correlation coefficient exceeding 0.97, confirming that the proposed sensoris feasible for salinity monitoring applications.