Impact of Measurement Uncertainty on Modeling of Dielectric Relaxation in Aqueous Solutions

Uncertainty analysis is performed on a coaxial probe-based dielectric spectroscopy measurement platform, and its impact on the modeling of dielectric relaxation in an aqueous solution is further analyzed. Based on the characterization theory and calibration principle of the platform, uncertainty due to the different available expressions and parameters of the calibration liquid is calculated. Then, repeatability uncertainty related to drift of the measurement platform, environment change, position variation of the probe immersed in the liquid under test (LUT), and so on is analyzed. Next, three types of water–alcohol mixtures and one group of glucose solutions are measured using the platform. Based on the measurement results, the best model is chosen to analyze the frequency dependence of the solutions’ relaxation properties. In addition, based on the uncertainty analysis, appropriate mathematical formulas are provided to model the composition dependence of the solutions’ relaxation parameters, which can be used as a liquid detection technique for chemical and biological applications.