Development Of A Portable Water Quality Analyzer Based On Color Sensor

Nowadays, our country’s water resource and water environment have someproblems: shortage of fresh water resource, severe waste of water resource and badlycontaminated of water quality. Especially in recent years, many serious waterpollution accidents occur and attract social concern. In order to build aresource-conserving and environment-friendly society, raise the level of ecocivilization and strengthen conservation of resource, our country needs to solve theproblem by enhancing the protection of environment and the capacity of sustainabledevelopment. On-site and rapid water quality detection and analysis could help todiscover water pollution timely, control the pollution and evaluate the effect ofdisposal.In the process of water quality analysis, adding different chemical reagent couldcause related chromogenic reactions. Based on the specific spectral absorption ofchromogenic substrate, we could get the concentration of some inorganic and organicsubstances in the sample. In this paper we have analyzed the Lambert-Beer Law andits additivity of complicated water sample, measured the color of solution based onRGB color sensing and established a liner relationship between the RGB absorbanceand the concentration of solute.In this development we designed a portable water quality analyzer based on RGBsensor and with characteristics such as a simple optical structure, highly integrated,low energy consumption, small size and easily to carry. The analyzer used white LEDas light source and a RGB sensor optical detector. Because different chemical reactionhas different color of solution, we analyze the transmission of light, the absorbance ofsolution and the light intensity. The analyzer used MCU as the core and completed theconvert and process of data. The analyzer also could store and display the result andachieve other functions.In this development, we carried out some relevant experiments to verify theperformance of the analyzer. By using the Shimadzu UV-Vis spectrophotometer forreference, we have analyzed the nitrite nitrogen solution, chromaticity solution andphosphate solution. With the rapid detection kit for water quality, we finally got the liner models used for test the parameters with related kits. The fitting degree is over0.99and in the experiment to analyze the actual water sample of nitrite nitrogen, therecovery is in the range of99%to122%.In this paper, we have developed a portable water quality analyzer based on RGBcolor sensor. This analyzer could offer a novel method with simple structure and easytest for on-site water quality analysis.