부산대학교 도서관

Electrical conductivity (EC) is one of the many water quality parameters that provides an indication of total ionic contaminants in water. This is traditionally measured with either lab-based equipment or battery-powered portable meters. These tools are expensive and require expertise to use, hindering their widespread adoption. We aim to address this challenge based on a custom-made electrode and processing unit that can be plugged into a smartphone via the USB port. In this paper, we present the design, development and evaluation of our mobile sensing system that is low cost (< 35 USD), easy-to-use (SUS score of 89.3) and accurate. Our initial testing suggests that the sensor is able to measure EC with < 3% root mean squared percentage error compared to a lab-based instrument. We believe our approach will empower a large group of people to contribute to water quality measurements.