We substantiate the need for a new method that can perform measurements in environments with low optical transparency and high viscosity. Based on prior studies and device capabilities, we note that express hydrocarbon monitoring requires instruments with broad capabilities to handle diverse media. We identify challenges that arise when monitoring the condition of fuel and engine oils using refractometric measurements. A new method has been developed to determine the composition of two‑component fuel mixtures (component concentrations) in express monitoring. The design of a refractometer operating on total internal reflection is proposed to implement this method. Various cases can arise when monitoring mixtures of fuels, such as fuel with engine oil or two engine oils. We provide measurement algorithms and reference tables to support implementation of the method. The results of studies of a mixture of two gasoline grades and engine oil with gasoline at different temperatures are discussed and support the method’s validity. Directions for further development and research are outlined.
Davydov et al. (Fri,) studied this question.