Метод сканирующей решетки питающих электродов одинаковой полярности
http://www.google.com/patents/US9256003
The invention discloses three-dimensional focusing induced polarization equipment for advance geological prediction of a water inrush disaster source in underground engineering, comprising a constant-current multiplex transmitter, an intelligent multichannel receiver, an automatic multi-electrode switch, an industrial personal computer, an observation electrode array and shielding electrodes, wherein electrodes in the observation electrode array are respectively used as a source electrode and observation electrodes; the industrial personal computer controls the constant-current multiplex transmitter to transmit currents of the same polarity to the shielding electrodes and the source electrode, so that the currents of the source electrodes are nearly directed straight ahead of a driving face under the action of the shielding electrodes;the observation electrodes are used for scanning data acquisition, and the data are fed back to the industrial personal computer through the intelligent multi-channel receiver; and the industrial personal computer controls the automatic multi-electrode switch to change the source electrode.

http://science.kuzstu.ru/wp-content/docs/OAD/Soresearchers/2...
В ходе измерений удельного сопротивления горных
пород применяют двух- и четырехэлектродные схемы на постоянном или переменном токе.
Двухэлектродные измерения, требующие бурения параллельных шпуров, чаще всего используются для оценки деформаций целиков, зон наибольшей концентрации напряжений, а также для контроля напряженно-деформированного состояния особо опасных участков ведения горных работ [4].
В четырехэлектродной схеме измерений используются пара питающих электродов АВ и пара измерительных электродов MN

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Note added at 15 hrs (2016-05-25 10:31:25 GMT)
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BACKGROUND OF THE INVENTION
China is one of the nations suffering most serious water inrush disasters in tunnel and underground engineering, casualties and economic losses caused by water inrush and mud inrush disasters are in the forefront of geological disasters of various tunnel and underground engineering, and heavy casualties and severe economic losses and environmental disruption are generally caused.


However, the existing advanced exploration induced polarization equipment in tunnel and underground engineering is fixed point source non-focusing type induced polarization equipment based on an electrical sounding theory.

The following key problems exist in the invention of the three-dimensional focusing type induced polarization equipment: (1) a shielding electrode and a source electrode need to simultaneously output current of the same polarity, and the invention of a multiplex large-constant-current transmitter with an automatic modulation function is the key problem; (2) in a three-dimensional focusing type induced polarization exploration method, an observation electrode system composed of tens of electrodes needs to be arranged on the excavation surface