A Low-Cost Water Quality Monitoring Based on Photodiode and LDR

Water is an important aspect that required by humans every day. The water quality is very essential on human's health. Nowadays, with the pollution that is affecting the water conditions, the quality of water consumed by humans need to be maintained. However, not every household have a dedicated system to monitor daily water quality. This paper proposed an alternative idea for utilizing several light sensors i.e. Light Dependent Resistor (LDR) and photodiode for detecting water quality especially its turbidity. This idea is proposed as an alternative solution to turbidity sensor and to have an affordable water quality monitoring system. Moreover, the sensor data is stored in a database on the Internet of Things cloud server and can be accessed by the Android- based application remotely. Based on the results, the system has successfully detected the water turbidity based on Nephelometric Turbidity Unit (NTU) scale. and the average sensor database update rate is about 16 seconds.