Each Potentiostat can be used as galvanostat. For this purpose, instead of the potential of the working electrode a voltage drop ES across an external resistor RX is used as feed-back control. The value of this resistor which is clamped between working electrode terminal of the potentiostat and its reference electrode terminal defines the range of the current Ic: Ic = Es / Rx Fig. 3: Potentiostat used as Galvanostat The current meter shows the actual current. To measure the potential, an external potential meter must be used, which is connected floating- i.e. it must not refer to ground - between the reference electrode and the working electrode. Note that the working electrode is not longer kept on ground potential now! The potential drop across Rx and according the cell current can be controlled by either the internal control source or an external source fed into the control input.
Fig. 3: Current Source (Galvanostat)
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