Non-contact measurement for alcohol concentration based on near-infrared absorption

In this paper, we designed a non-contact measurement system of alcohol concentration based on near-infrared absorption. The system measures the absorption spectra of alcohol solutions with known concentration, and explores the relationship between solution concentration and absorbance. The results show that the linear correlation between the absorbance value and the solution concentration is more than 0.99, which is in good agreement with the theory. The least-squares method was used to fit the absorbance and alcohol concentration to establish the functional relationship. Besides, the incident light intensity and transmitted light intensity of the alcohol solution are measured to calculate the absorbance of alcohol solutions of different concentrations and then obtain solubility information of alcohol solutions. This system is characterized by simple structure and accurate and reliable measurement, which can effectively improve the efficiency of solution concentration measurement. In addition to measuring the concentration of alcohol solution, this program can also be applied to measure the concentration of other solutions, only with a light source of appropriate wavelength and the corresponding photoelectric detector, so the design of the program has a very broad application prospects.