Short note on electrode charge-up effects in DC resistivity data acquisition using multi electrode arrays

The measurement sequence used in DC resistivity data using multi-electrode arrays should be carefully designed so as to minimize the effects of electrode charge-up effects. These effects can be some orders of magnitude larger than the induced signal and remain at significant levels for tens of minutes. Even when using a plus-minus-plus type of measurement cycle, one should avoid making potential measurements with an electrode that has just been used to inject current, as the decay immediately after current turn-off is clearly non-linear.