A TD-FD combined method for enhancing reflectometry measurements in liquid quality monitoring

Quality measurement techniques for fluid-related industry applications, require difficult procedures and the process control, associated to the permittivity monitoring, limits the use of traditional sensing technologies. In this paper, a complete investigative path based on time-domain reflectometry (TDR) and frequency domain analysis is presented, in order to appropriately improve the measurement of the frequency dependent dielectric characteristics over a wide range of fluids, even when lossy liquids are involved. The proposed approach conjugates low-cost and portability with the real time monitoring capability, paving the way to the use of the proposed method in many industrial areas.