Noise-rejection techniques for impedance and dielectric spectrometers using ubiquitous test and measurement equipment

This work encompassed the development for a frequency-domain impedance and dielectric spectrometer using ubiquitous test and measurement equipment, i.e., signal generators and digital oscilloscopes. Various methods of amplification, noise rejection, and computations were employed to achieve the desired goals. The frequency range of 100 mHz-1 MHz was tested using air capacitors of 3.7 and 14.5 pF and an applied voltage range of 10-300 mV. The multichannel instrument produced a stable and reproducible dual-phase (real and imaginary or magnitude and phase) current sensitivity of 250 fA with an average phase stability of less than 0.5 degrees (tan delta<10(-2)) and a single-phase (magnitude only) current sensitivity of 60 fA.