Optimized Microwave Sensor for Online Concentration Measurements of Binary Liquid Mixtures

This paper describes microwave sensors designed for online measurements concentration of binary liquid mixtures. It is based on the cylindrical resonator having axial glass tube filled with the liquid under test. The input coupling element has been optimized using 3D EM simulator (CST Microwave Studio) in order to reach maximum sensitivity and concentration resolution. The sensor can be calibrated for a variety of organic and inorganic binary mixtures. Examples of operation of the sensor with mixtures such as water-methanol, magnesium-sulphate, and water-sodium chloride-glucose are reported.