Most Accurate or Fastest Possible? The Multi-Frequency SIP Excitation Enables a Choice

Abstract

Summary The Spectral Induced Polarization (SIP) method measures the frequency dependence of the electrical resistivity of rocks and sediments by magnitude and phase. Usually, the resistivity spectrum is measured sequentially with mono-frequency signals. This method proves to be advantageous for large-scale measurement set-ups and high interference voltages, as it provides the highest measurement accuracy. For small-scale field measurements or laboratory measurements, interference voltages often play only a subordinate role. Here, it is also important to achieve the highest possible measurement progress. This can be doubled by multi-frequency excitation compared to mono-frequency excitation. However, the price of faster measurement is a somewhat higher measurement error. We have implemented and successfully tested both excitation techniques in a new 88-channel laboratory measuring instrument (SIP-LAB-FAST). The user now has the choice between the most accurate or the fastest possible measurement. He can thus optimally adapt the measurement process to the requirements of the object under examination.