An uncertainty analysis for the measurement of microwave conductivity and dielectric constant by the short-circuited line method

The uncertainties of conductivity σ and dielectric constant ε of the short-circuited line (SCL) method due to the measured errors in the VSWR and the position of standing-wave minimum are studied. In order to cover most of the fast ion conductors, the range of σ from 10^-4 to 1.0/(Ω-cm) is considered. The results of the analysis provide the order of accuracy one can achieve in these measurements. The effects of sample thickness, high conductivity, and negative dielectric constant upon uncertainty are examined. Measurements on a chlorobenzene sample are used to simulate this analysis. A relationship between σ, ε, and operating frequency is derived which makes it possible to determine the limits of applicability of the SCL method.