A Time Domain Reflectometer for Dielectric Relaxation Spectroscopy of Electrolyte Solutions

A time domain reflectometer for dielectric relaxation spectroscopy of electrolyte solutions in the temperature range of −;45 ≤ ϑ /°C ≤ 90 is presented. With a set of cutoff cells differing in their cell constants, pure solvents covering the permittivity range of 7 ≤ ϵ ≤ 228 and their concentrated electrolyte solutions (κ > 1 Ω⁻¹ m⁻¹) can be investigated at frequencies of 0.05 ≤ v/GHz ≤ 9. In combination with the transmission line system of our laboratory (8.5 ≤ v/GHz ≤ 89) dielectric dispersion, ϵ′(v), and total loss, η″(v) = ϵ″(v) + κ/(2π vϵ₀) can be determined with 2% accuracy relative to ϵ.