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Updated: Aug 4, 2025

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation
Published on: October 10, 2018
New method for determining time constant of resistors
Yicheng Wang1, Dean Jarrett1, Andrew Koffman1
1Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Abstract:
We report a new method for determining the time constant of ac resistors with values around 10 kΩ using a digital impedance bridge for the comparison of two nominally equal resistors. This method involves adding a probing capacitor in parallel to one of the resistors to induce a quadratic frequency dependence in the real component of the admittance ratio between the two resistors. The magnitude of this quadratic effect is proportional to the self-capacitance of the unperturbed resistor, enabling us to determine its value and the associated time constant with an estimated standard uncertainty (k = 1) of 0.02 pF and 0.2 ns, respectively.
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