Description
Run the Multi-Step Chronopotentiometry standard technique by selecting Experiment > Physical Electrochemistry > Multi-Step Chronopotentiometry from the Framework™ menu bar. This initiates the following sequence of events:
1.Framework™ creates a Runner window, and the Multiple-Step Chronopotentiometry.exp script is run in this window.
2.The script creates the Setup dialog box which becomes the active window and accepts changes in the experimental parameters. This Setup window remembers the experimental settings from the last time this script was run. To restore the parameters to the values defined in the script, click the Default button. If the Advanced Pstat Setup is in the On position, a second Setup dialog box containing hardware configuration details becomes the active window, allowing you to modify the hardware configuration used during the experiment.
3.The script now obtains the use of the potentiostat specified during Setup and opens the data file using the Output name. If the potentiostat is in use or the file cannot be opened, the script returns you to the Setup dialog box. The file header information is written to the data file. This information is written to the file prior to data acquisition. If the experiment is aborted, the file contains only this information. This header information includes:
•Tags identifying possible analyses.
•The current time and date.
•A list of the Setup parameters.
4.If Initial Delay is on, then the cell is turned or left off and the specimen's Eoc is measured for the time specified as the Initial Delay time, or until the potential stabilizes to a value less than the stability setting. A plot of potential versus time is always displayed. The last measured potential is recorded as Eoc. If Initial Delay is off, this step is skipped and Eoc is assumed to be 0.0 V vs. Eref.
5.The script conditions the electrode if Conditioning was specified in the Setup. Conditioning is done by applying a fixed potential for a defined time. It establishes a known surface state on the corrosion specimen. A plot of current versus time is displayed during the Conditioning. No data are saved during this step.
6.Finally, the data acquisition process starts. The current is stepped to Step 1 Current and held at that value for Step 1 Time. The current is then stepped to the subsequent step current and held at that value for set time. Steps are skipped if the subsequent step times are zero. Voltage and current readings at fixed time intervals (Sample Period) are taken during the steps in Multi-Step Chronopotentiometry.
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If at any time the measure voltage exceeds the Limit Voltage, the current step is terminated, and the experiment proceeds to the next segment of the applied signal. Plots of E and I vs. time are displayed during the steps. |
7.The data are written to the output file, and the script cleans up and halts.
8.When the scan is over, the cell is turned off. The acquired data are written to the output file.
9.The script then waits for you to click the F2-Skip button. When you do, the script closes everything that is open, including the Runner window.