Ambiguity in induced polarization time constants and the advantage of the Pelton model

The perceived differences between two popular relaxation models (referred to here as the “Cole-Cole model” and the “Pelton model”), along with their corresponding time constants, have been a source of confusion in recent spectral induced polarization (SIP) literature. These differences complicate comparisons among experimental results recorded by different researchers. A circuit model approach is adopted to better understand the differences among these relaxation models. Either relaxation model can fit SIP data sets equally well, the sole difference corresponds to the relaxation time that varies for the impedance and admittance formulations of the circuit models. The reporting of time constants from a common relaxation model will advance petrophysical investigations of the controls on SIP measurements when exploring databases compiled from previously published data sets.