Rapid Estimation of Ethanol Concentration using Acousto-Optic Diffraction

Fast and accurate determination of ethanol concentration is important in alcohol industries for testing the purity and quality of their products. Here, we demonstrate a quick, robust, and accurate technique to estimate the concentration of ethanol in aqueous solutions. Our method utilizes the principle of diffraction of light in the presence of high frequency ultrasound waves that create diffraction grating in solution. A monochromatic light interacts with this acoustic grating and produces an intensity distribution pattern, which was used to determine the ethanol concentration. We measured ethanol concentrations in various alcoholic solutions and beverages at room temperature with very high accuracy down to 2 % over a concentration range of 30–100 %. The experimental results have been supported with analytical calculations and simulations. We believe that our method will benefit alcohol production industries and lead to the development of portable, inexpensive, and reliable ethanol concentration measurement devices.