Modular high-precision dielectric spectrometer for quantifying the aging dynamics in (Sub-)picofarad polymeric specimens

A custom-made modular high-precision dielectric spectrometer for quantifying aging-induced molecular changes in (sub-)picofarad polymeric samples is presented. Validation and characterization of the setup's performance is obtained by quantifying the change in the dielectric response of an epoxy polymer following the exposure to thermal, hygrothermal and ultraviolet radiation stress. It is shown that the observed changes in the dielectric spectra can be resolved with a relative precision better than 5·10
^-5
and are in line with previous studies employing commercial instruments on samples of higher capacitance. This setup is intended to serve as a blueprint for a sensitive and extensible (because modular) measurement tool for studying the pre-breakdown dynamics in low-capacitance recessed or disc-shaped specimens as used, e.g., in high-voltage insulation testing.