Complex Impedance as a Diagnostic Tool for Characterizing Thermal   Detectors
  The complex ac impedance of a bolometer or microcalorimeter detector is easily measured and can be used to determine thermal time constants, thermal resistances, heat capacities, and sensitivities. Accurately extracting this information requires an understanding of the electrical and thermal properties of both the detector and the measurement system. We show that this is a practical method for measuring parameters in detectors with moderately complex thermal systems. 
John E. Vaillancourt (University of Wisconsin - Madison)