Induced polarization

Induced polarization (IP) is a geophysical imaging technique used to identify subsurface materials, such as ore. The method is similar to electrical resistivity tomography, in that an electric current is induced into the subsurface through two electrodes, and voltage is monitored through two other electrodes.

Time domain IP methods measure the voltage decay or chargeability over a specified time interval after the induced voltage is removed. The integrated voltage is used as the measurement.

Frequency domain IP methods (see Spectral Induced Polarisation) use alternating currents (AC) to induce electric charges in the subsurface, and the apparent resistivity is measured at different AC frequencies.

References

• Kearey, Philip; Michael Brooks (1991). An Introduction to Geophysical Exploration (Second ed.). Blackwell Science. ISBN 0-632-02923-4.

External links

• Example IP equipment and image results