The Desing And Implementation Of Automatic Lovibond Colorimeter

Oil is the essential nutrients of our body, color determination is one of the important indicators of oil quality testing, and plays an important role in improving oil quality. In recent years, there many methods of color determination, which includes The Visual Method, Photoelectric Integration Method, Spectrophotometry and so on. Take consideration of precision and costing, it’s necessary to research and development an automatic colorimeter.With the disadvantages such as time-consumed, high labor intensity and human error of Lovibond visual colorimeter, this topic first proposed the problems that need to be resolved and the difficulties may encounter. Then designed research scheme according to the above-mentioned problems, the research scheme mainly done the fowling works:on the one hand, constructed a hardware platform for our automatic Lovibond colorimeter, the system can be divided into three parts, those are data acquisition module, data processing module and data displaying module. The data acquisition module is mainly composed by the light source and the color sensor, which is responsible for collecting the sample’s color signal and then sent them to the microcontroller. Microcontroller as the core module of the system, which is responsible for data processing, the data that collected by color sensor is the brightness of the samples’, which much be converted to the values of Lovibond color space. This values will be last displayed on the tube, which we call it display module. Bilinear interpolation method was used in the conversion between RGB color system to the Lovibond color system. We know that the values that color sensor obtained are based on three-primary colors of RGB, instead of RYB, which are the three-primary colors of oil, so bilinear interpolation method is necessary. Finally, we had done three experiments to verify the stability and accuracy of the system, from the experimental results, it can be proved that the system is accurate and stable. The instrument had complete following functions:first, White balance, it comes when the light source or color sensor changed; second, measuring, completing the color measuring of the samples, and displays on the tube; Third, print, you can print out the results as if it is connected to a printer.