EC-Lab Technical Notes 40: Influence of the current range on the response time of a potentiostat

Introduction

The response of a system to a voltage or current step is not instantaneous. It is shown in this note that the response time of the potentiostat/galvanostat in Chronoamperometry (CA, potentio control) and Chronopotentiometry (CP, Galvano control) techniques, or more generally in voltage or current control techniques, depends on both the studied system and the range of current measurement. This note shows the influence of the current range on the response time in both voltage and current control of the cell. Assuming that the same cell is stressed in the same way by a potentiostat, the choice of the current range will have an influence on the potentiostat response time. For the sake of simplicity, the experiments were conducted on a simple resistor dummy cell with the help of an SP-300 instrument running CA and CP techniques. A theoretical analysis explains the experimental results.