Chronoamperometry (CA) and chronocoulometry (CC) have the same potential wave form - the potential step - which is one of the simplest potential wave forms. As shown below (Fig1), the potential is changed instantaneously from the Initial Potential to the First Step Potential, and it is held at this value for the First Step Time. This is a single potential step experiment. In a double potential step experiment, the potential is changed to the Second Step