Repeating Chronoamperometry

Run a Repeating Chronoamperometry test by selecting Experiment > Physical Electrochemistry > Repeating Repeating Chronoamperometry on the Framework™ menu bar.

This is an extension of Gamry Instruments’ Chronoamperometry script. It allows the user to repeat a Chronoamperometry test over multiple cycles. The number of cycles must be a positive integer.

This is a multipurpose test. Many uses involve modification of an electrode surface. If the applied voltages are sufficient to form and then reduce an oxide layer on the electrode, repeated cycles usually roughen the electrode. Another use is mimicking excitation pulses in biological/electrochemical applications.

The Setup window for Repeating Chronoamperometry is identical to that Setup for Chronoamperometry, except for the addition of a Cycles parameter.

Each cycle generates m data points, where:

m = Step 1 Time / Sample Period + Step 2 Time / Sample Period

The total number of points in the data curve is Total Points:

Total Points = Cycles × m

Immediately after Setup, the number of points required for the test is compared to the maximum points allowed in a Chronoamperometry curve. If you asked for more than the allowed number of points, an error window appears. You can resolve the problem by:

Increasing the Sample Period

Reducing the Cycles

Reducing the Step Times

When the test is run, all pre-step actions (Conditioning, Initial Delay, etc.) are performed once. The script then:

  1. Applies the Step 1 Potential for the Step 1 Time,
  2. Applies the Step 2 Current for the Step 2 Time,
  3. Increments a completed cycles counter,
  4. Stops the test if the completed cycles counter exceeds the Cycles parameter
  5. Loops back to Step 1 if more cycles are needed

The result of the test is a curve containing current- and voltage-versus-time data points. All the steps are contained within one data curve.

The data file can be opened in our Echem Analyst™ program.