Electronic Design of a Prototype for the Optical Characterization of Liquids and Prediction with a Rule-Based System

Water quality monitoring has been widely studied over the years due to the important role water plays on our planet. Much research using the optical characterization of different materials has been done for the medicine, agriculture, and food industries. Usually, for optical characterization, turbidity sensors and spectrometers are mostly used. However, with the improvement of technology for the semiconductor industry, this project proposes to study optical properties such as transmission and diffuse reflection of different colored liquids with photodiodes and LEDs as an alternative of using spectrometers. It is proposed to give an insight into the state of water by using more affordable sensors in the market so the prototype would be easily reproducible, and accessible at a low cost.
This project presents the design and implementation of a prototype for the optical characterization of distilled water containing different non-toxic solutes. For the experiment, 4 different food colorants were used and systematically varied in their concentration to test the prediction of the color and concentration of colorants using a rule-based system. The prototype developed was designed to be an effective low-cost alternative to the use of spectrometers. The project is expected to serve as a basis for further experiments and investigations for optical characterization of different liquids and LED/photodiode combinations.