How to use Induced Polarization (IP) method ?

How to use  Induced Polarization (IP) method ?

The Induced Polarization (IP) method extends the resistivity method by making an additional

measurement of the ability of the ground to store electrical charge. Originally developed for mineral

exploration, it is now finding new applications in the fields of environmental and engineering geophysics.

IP instruments measure both the conductive and capacative properties of the subsurface using either

time domain or frequency domain techniques. The low frequency capacitance of rocks and soils is

primarily a function of the surface chemical properties of the sample. In non-metallic samples the IP

response is an indicator of surface area and charge density of the material. IP measurements are

therefore sensitive to clay content as well as mineralogy and pore fluid composition. IP methods have

been used to estimate the hydraulic properties of rocks and soils as well as to map subsurface

contamination. The method is also sensitive to subsurface metals

Routine use of IP in near-surface studies has been hindered by an incomplete understanding of the

physical and chemical processes governing the IP response. Inadequate instrumentation and

interpretation software were also limiting factors. Recent advances, however, from laboratory

investigations, new instrumentation and software development have overcome many of these limitations.

In this review we summarize these recent advances and discuss how the IP method can be applied to

engineering problems. Applied research in engineering applications of the IP method should prove

lucrative and be encouraged.